Historical Review.39—It is impossible to state when and how the knowledge of the value of antiscorbutic foodstuffs came to be appreciated. It is probable that the potency of herbs and fruits in scurvy was known empirically to individuals and groups of people long before the fact gained general recognition. A most interesting history of antiscorbutics is given in the excellent work of Hirsch and in our great classic on scurvy by Lind. The first realization of the value of lemons and oranges seems to have been the result of a chance discovery. Budd tells us that in the sixteenth century sailors of a Dutch sailing vessel laden with these fruits were attacked with scurvy, and that, when they partook of the lemons and oranges in the cargo, a miraculous cure resulted. He narrates also the following striking incident, which is mentioned likewise by Lind:

In the year 1600 four sailing vessels left England for the East Indies. The sailors on three of these ships did not receive lime juice, whereas those on the fourth received their daily quota. The men of the first three ships suffered severely from scurvy, but those on the fourth escaped.

In an excellent work on “Scorvey,” published in 1685, Harvey wrote: “Wherefore most acids, especially spirit of salt marine, juice of sorrel, limons, citrons, etc., are so deservedly extolled in some scorbutic distempers and seconded with good success.” Thus we see that even at this early date it was taken for granted that citrous fruits possessed virtue in curing scurvy. Bachstrom (Observationes circa Scorbutum, 1734) evidently was well-acquainted with the antiscorbutic value of scurvy grass, and relates the story of a sailor severely disabled from scurvy who was put ashore to perish on Greenland, and crawled on the ground, grazed on scurvy grass like a beast of the field, and was able to return home perfectly recovered. (Cited from Lind.)

The credit for forcing a general acceptance of the antiscorbutic value of fresh food belongs to Lind. He did not, however, have an easy task, and in 1747, in order to convince those who still were skeptical, he resorted to an experiment on human beings. Twelve patients in his hospital were given the same diet, except that some received sea-water in addition to their dietary, others vinegar, or elixir of sulphuric acid, or a daily portion of cider, or oranges and one lemon daily. The last two groups, as we should expect, recovered quickly; one man who received cider improved, but in no other case was any alleviation noted.

Lind extols the value of lemons and oranges, of berries, of sour cabbage, of cider, and of all fresh fruits and vegetables. In spite of the fact, however, that Lind’s teaching was based on an experience with thousands of patients suffering from scurvy in the naval hospital, his ideas did not take root. It required an event which came directly under the official eye to bring about radical changes in the diet of the sailors. In 1795 the English Fleet suffered from a severe epidemic of scurvy, which was finally controlled by giving the sailors fresh vegetables and fruit. This therapeutic result was so convincing that thenceforth a daily ration of lime juice was ordered for the sailors and a regular issue provided for the navy. This marks the cessation of scurvy as a scourge of the British navy. From this time the disease appeared only sporadically. The sharp decrease in the incidence can be appreciated by Budd’s statement that 1457 cases of scurvy were admitted to the Royal Naval Hospital in 1780, whereas in 1810 an English physician reported that in the seven preceding years he had not treated a single patient in this hospital suffering from scurvy. In another marine hospital, between the years 1806 and 1810, only two cases of scurvy were admitted.

Nothing was done for the British merchant service until over half a century later, although scurvy continued to make its appearance among the sailors with varying severity. Smith states in the article on this subject in Allbutt’s System of Medicine: “In 1864 it was pointed out by Doctor Barnes that during the twelve years following 1851, 1058 cases of scurvy had been admitted into the hospital ship Dreadnought.” In 1854 a law was passed requiring every vessel to carry an adequate supply of lime juice. This law, however, failed in effect, due to the fact that a large part of the lime juice was adulterated. A new shipping-act was passed, therefore, in 1867, with the object of preventing adulterations, at the same time increasing the daily quota for each seaman from half an ounce to one ounce.

It may be of interest to add a few words concerning certain antiscorbutics which have been under discussion or recognized for so many years that they have acquired an historical aspect. One of these foodstuffs is sauerkraut, which was recognized by Lind in 1772 as having particular potency in this disease. It is interesting to note, in this connection, that this writer appreciated the close relationship of acidity to antiscorbutic virtue. “One quality,” he writes, “entering the most perfect antiscorbutic composition is a vegetable accescency.” He prized sauerkraut for its inherent value, and particularly, because he found that “sour cabbage will keep for an East-India voyage.”

The famous navigator Cook, whose voyages were remarkable for the freedom from illness which his sailors enjoyed and the absence of scurvy, always kept a large supply of sauerkraut on hand. It was believed by many that the immunity of the Dutch seamen to scurvy was due to their large consumption of this vegetable. As the result of this empirical knowledge, the English navy in 1780 introduced the use of sauerkraut into its ration. As just noted, however, this antiscorbutic was supplanted some few years later by an issue of lime juice.

It is common knowledge that outbreaks of scurvy follow closely upon a failure of the potato crop. This has been particularly the case in Ireland, where it was especially evident in relation to the great epidemic of scurvy in 1847. Holst and Froelich inform us that “all scurvy epidemics in Norway in the nineteenth and beginning of this century followed failure of the potato crop.” Nor is this danger past. In an article entitled “The RÔle of Antiscorbutics in Our Dietary,” the author recently reported that the partial failure of the potato crop in the eastern part of the United States led to the development of scurvy in numerous institutions, in one of which over 200 cases of definite scurvy developed in the spring (1916).

The occurrence of scurvy in the navy and on sailing vessels has been associated in the minds of many with the large amounts of salted meat which necessarily was included in the dietary. It was evident that meat that was salted had no antiscorbutic value, but the query has been raised whether eating a considerable amount of salted meat did not induce scurvy. Lind mentions “flesh long salted” as leading to the development of scurvy. The question of the value of meat as an antiscorbutic is of importance at the present time, chiefly in connection with Polar expeditions and army rations. As the result of an outbreak of scurvy in the Polar expedition of 1875–6, a British Arctic Survey Committee was appointed to make an investigation. In 1877 it reported that “although the scurvy was due to the absence of lime juice from the sledge dietaries, meat in large amounts is able to prevent the disease.” StefÁnsson also emphasized the value of meat in preventing scurvy in the Polar regions. In his expeditions he has found that raw meat, if taken in sufficient quantity, is able to afford complete protection. Jackson, who lived for some years among the Samoyeds, tells us that this tribe, owing to the fact that they consumed considerable reindeer meat, never suffered from scurvy in spite of the fact that they ate no vegetables or fresh fruit during the winter.

The following account, a personal communication from Dr. Harrison J. Hunt, who spent four years in the Arctic regions, is of interest in this connection:

“For some four years I was with the Smith Sound Eskimos, on the northwest coast of Greenland. These people get nothing but animal food normally, and have lived that way for many generations, yet are healthy, of good physique, and are normal in other ways. Scurvy was unknown to them as far as I could ascertain; certainly there was none while I was among them. Much of their meat is eaten raw, and the rest only partly cooked; that is, ‘rare done.’

“Whalers who were accustomed to winter in Hudson Bay practically always had scurvy in the crew. It was common knowledge among the captains that fresh meat was curative of scurvy, and it was their practice to obtain meat from the Eskimos whenever possible for that purpose. The last English expeditions to the South Polar regions were afflicted with scurvy which was entirely and quickly eradicated by the use of fresh seal meat in the place of salt meats and canned foods. They do not state that this meat was eaten raw or even rare cooked. On the Danish coast of Greenland, during seasons poor in game, scurvy is quite common, but the natives there live largely on breadstuffs (very coarse rye bread). Personally, during my four years in the Arctic, I took no fresh vegetables whatever, or other commonly-called antiscorbutics, relying solely on rare or raw meat. I never was stronger or more healthy in my life. I did have dried fruits and vegetables, and usually plenty of fresh bread. Usually the Eskimos eat their raw meat in a frozen condition, and I can attest that it is extremely palatable in that condition.”

We do not wish to discuss, in this place, the value of meat as an antiscorbutic; in passing, however, it may be said that, as in the case of the other antiscorbutics, its efficacy will depend largely upon the amount consumed. The British Mesopotamia Commission Report of 1917 shows that scurvy can develop on a ration which includes 28 ounces of meat a week. We must remember, however, that this refers to cooked meat, whereas in the Polar expeditions meat generally was eaten in a raw state.

Recently an historical inquiry has appeared in an article by Chick, Hume and Skelton as to the antiscorbutic virtue of limes and lemons. This sketch is of exceptional interest because it treats of the oldest and most cherished antiscorbutics, and particularly because it has unearthed a peculiar fallacy in their connection. As they state, there would appear to be every reason for believing “that the use of so-called lime juice was responsible for the disappearance of scurvy from the British navy in the first decade of the nineteenth century.” It would seem, however, that the lime juice which gained this great reputation in the navy some 125 years ago was in reality lemon juice, and that it was not until about 50 years ago that lime juice was really used. These authors show—by one of those striking human experiments which, occasionally, is available—that in a Polar exploration which was organized in 1850 lemon juice was issued to each man, and that no case of scurvy developed, whereas in a similar expedition which went out in 1875 lime juice was issued and scurvy developed the following spring with great severity among the sledge crews. This investigation, therefore, seems to prove that lime juice, the prototype of antiscorbutics, has been accorded a false position; that in reality the sailors of the past have been protected by lemon juice.

Antiscorbutic Foods.—As far as has been ascertained, the antiscorbutic food factor exists in all fresh vegetable and animal tissues, being present to a far greater degree in the former than in the latter. It is distinguished by being associated in nature with cells which are the seat of active metabolism, just as the water-soluble vitamine is associated mainly with cells which are in an inactive or dormant state. Vegetables or fruits may be mildly or highly antiscorbutic; there is indeed a remarkable difference in their content of antiscorbutic factor or vitamine. They vary widely also in the degree to which their potency is affected by physical or chemical conditions. In this chapter the most common animal and vegetable antiscorbutic foodstuffs will be considered and the effect which processes such as drying, canning, change of reaction, etc., exert on their specific value. Their therapeutic application in the prevention and cure of scurvy will be considered in a subsequent chapter. Until recently our knowledge of this subject was empirical and inaccurate; as the result of scientific work, however, carried out during the past few years in different parts of the world, quantitative and comparative figures of antiscorbutic food values have been evolved.

Milk.—It is important to have as accurate an idea as possible of the value of milk as an antiscorbutic, as the infant depends on it during the first months of its life for a supply of this essential factor. Considerable attention has been paid to this question in the last few years, and recent reports tend to confirm the former estimations which had been overlooked and forgotten. In 1847 Curran wrote that in the Irish epidemic of this year they had admitted to the Dublin Union Hospital 80 cases of scurvy which had been on a diet which included one pint of milk daily, but was deficient in vegetables. From this experience he realized that milk was not rich in the principles which protect against scurvy. In the following year Parkes came to the same conclusion, stating that 500 to 750 c.c. of raw milk did not always suffice to prevent scurvy. In addition to these opinions concerning adults, similar conclusions have been drawn from clinical experience with infants. Barlow (1894) realized that a small amount of milk was insufficient to protect against scurvy. Still writes: “The antiscorbutic power of fresh, unboiled milk is evidently slight.” In 1914 Hess and Fish pointed out that “milk must not be considered as having potent antiscorbutic properties.” Nevertheless, when this question was raised recently by the experimental work of Jackson and Moore, and that of McCollum and Pitz, it was not appreciated that, like other antiscorbutics, milk must be regarded from a quantitative standpoint, and that, as it is a weak antiscorbutic, its effect must depend largely on the quantity consumed.

The first laboratory work on this subject was that of Froelich in 1912, who showed that guinea-pigs could be protected by an exclusive diet of fresh milk, and that raw milk is more effective than heated milk. In his work, the amount of milk taken by the animals was not measured, so that it is impossible to glean from it more than these general conclusions. In the following year, as a result of some quantitative experiments, Funk stated that he was able to protect guinea-pigs with 50 c.c. of fresh milk in addition to an oat diet. This estimate, as subsequent workers showed, is too low. Chick, Hume and Skelton were the first, however, to investigate the antiscorbutic potency of milk in a systematic and convincing manner. They demonstrated that if the daily consumption of fresh milk was less than 50 c.c., a guinea-pig died almost as quickly as if it received no milk; if the daily quota varied from 50 to 100 c.c., a greater or less protection from scurvy was observed, varying proportionately with the amount consumed; if 100 to 150 c.c. were taken daily, which practically amounts to a complete milk diet, satisfactory growth and development occurred, and no symptoms of scurvy were observed. This represents in a general way the present conception of the antiscorbutic power of milk. In passing, it may be remarked that it is not altogether clear why 50 c.c. of milk do not afford partial protection, and prolong the life of the animal for a definite length of time. The authors conclude that “milk is evidently a food poor in the antiscurvy accessory factor, and a ration large in comparison with that of other antiscorbutic materials is necessary to afford satisfactory protection from scurvy.” The error must be avoided, however, of regarding milk as a standard article of diet containing a definite and specific amount of vitamine per cubic centimetre. It will be shown later that this point of view cannot be taken in regard to vegetables, and it is probable that it cannot be assumed for milk.

A general conception of the antiscorbutic potency of cow’s milk may be gleaned from the fact that it requires a minimum of about sixteen ounces (500 c.c.) daily to protect an infant from scurvy or to cure it. Twelve ounces have failed to effect a cure in several instances, although the milk was raw and of the best grade. If it is pasteurized, a larger quantity is required, depending upon various conditions connected with the heating process and upon the age of the milk, circumstances fully discussed in relation to etiology. Thus it becomes evident that pasteurized milk assumes a two-fold rÔle, acting as an antiscorbutic if little of its vitamine content has been destroyed and if a large quantity is consumed, or leading to the development of scurvy when one or both of these conditions is unfavorable. The same holds true for milk which has been boiled for a short period. If the milk has been heated twice, it tends to produce scurvy; if it is condensed, the greater part of its antiscorbutic value is destroyed.

It seems necessary to emphasize again the important fact that dried milk may possess marked antiscorbutic potency, depending on the method of preparation (Fig. 11). As stated, sixteen ounces of milk dried by the Just-Hatmaker process cured scurvy promptly, in spite of the fact that the milk had been dried six months previously. Here, therefore, is a food of high caloric value, compact, antiscorbutic, and stable. The fact that milk, in spite of drying, retains this labile vitamine for so long a period, demonstrates that it is available in the most remote parts of the world, and that the possibilities of its transportation are unlimited.

Little is known regarding the antiscorbutic content of the milk of the various domestic animals. Some claim that goat’s milk is notably rich in this particular, but experiments with it are too few to warrant conclusions. Lind writes: “Goats, of all animals, afford the richest whey, possessed of the greatest antiscorbutic virtue... which in a singular manner restores the constitution when weakened and impaired by scurvy.” Human milk possesses about the same potency as cow’s milk, as mentioned in the discussion of the occurrence of infantile scurvy in countries where the adult form is endemic. Twelve ounces of human milk, from a woman on a liberal and varied diet, barely sufficed to alleviate the symptoms of a case of moderate intensity.

FRUIT JUICES

Orange and Lemon Juice.—The most thoroughly studied antiscorbutic foods are orange and lemon juice, which have been singled out because they contain the antiscorbutic factor in the highest concentration. It has been ascertained through the work of various investigators that guinea-pigs require about 3 c.c. daily of either of these juices to protect them from scurvy, but that about half this amount is sufficient to prevent the manifestation of clinical signs.

Both of these juices withstand heat remarkably well. Orange juice can be boiled for 10 minutes without noting any diminution of its antiscorbutic value, and lemon juice heated to 110° C. without appreciably losing its efficacy. However, orange juice undergoes some change as the result of being heated in an autoclave for 45 minutes at a temperature of 110° under 10 to 15 pounds pressure. Although 6 c.c. of this heated preparation were able to prevent the development of scurvy, the guinea-pigs did not gain nearly as well as those which received 3 c.c. of the unheated juice. It seemed as if there was a destruction of some factor apart from the antiscorbutic principle.

In spite of the fact that these juices withstand heat well, they are sensitive to some other conditions. Orange juice which had been stored in the cold for three months was unable to protect guinea-pigs in the dosage of 3 c.c. per animal, resembling in its action the autoclaved juice. When this orange juice was six months old, double this quantity failed to protect; throughout this period it was kept in the ice-box and covered with a layer of oleum petrolatum to avoid the access of air or possible contamination. Harden and Zilva met with a similar experience, and state that “after storing treated (concentrated) lemon juice for about a fortnight in a cold room, a marked loss can be observed in its potency.”

These authors reported also that when orange juice is rendered slightly alkaline it loses its antiscorbutic potency. This question was investigated in relation to canned tomato juice, as well as to orange juice, and it was found that shortly after having been rendered 0.05 N alkaline to phenolphthalein, neither of these foods had lost an appreciable amount of its antiscorbutic factor. Five cubic centimetres per capita daily of freshly-alkalized orange juice were able to cure a group of pigs which had developed scurvy on another diet. If, however, 24 hours were allowed to elapse instead of only one-half to one hour, between the alkalization and the feeding, then a considerable amount of the antiscorbutic factor was lost. The same general rule seems to hold for alkalization as for heating, i.e., the length of time the antiscorbutic food is subjected to the deleterious influence is fully as important as the intensity of the process. Advantage has been taken of the fact that freshly-alkalized orange juice retains its potency, in using it intravenously in the treatment of infantile scurvy.

Subcutaneous injections of neutralized orange juice failed to cure scurvy in guinea-pigs; Harden and Zilva were equally unsuccessful with large doses of their concentrated lemon juice. This is of interest in view of the marked therapeutic result which Shiga obtained with subcutaneous injections of the water-soluble vitamine in pigeons suffering from polyneuritis. It should be added that Holst and Froelich (1912) failed to cure scurvy in guinea-pigs by intraperitoneal inoculations of orange juice.

Lemon juice or orange juice may be dried and lose little of its antiscorbutic power. In their paper of 1912 Holst and Froelich reported the efficacy of lemon juice evaporated in a vacuum, and recently Harden and Zilva published experiments which proved that “by evaporating the treated lemon juice to dryness in an acid medium an active dry residue is obtained.” Still more recently Givens has shown that orange juice reduced to a powdered form by means of a spraying process has lost little of the antiscorbutic factor. These results prove that under certain conditions the antiscorbutic factor withstands drying; one of these favorable influences is an acid reaction, and another, rapidity of desiccation.40

Lime Juice.—Recently an investigation of lime juice has been carried out by Chick, Hume and Skelton. They were “unable to detect any significant protection in a daily ration of from 5 to 10 c.c. of preserved lime juice which was several months or a year or more old.” Crude lime juice of various ages had slight antiscorbutic value, affording only partial protection in a daily ration of 5 c.c. Even fresh juice was found not to be very efficacious compared with lemon juice. The authors conclude that “the relative value of these two fruit juices deduced from the trials with monkeys is therefore in accord with that obtained in the experiments with guinea-pigs, i.e., the value of fresh lemon juice is approximately four times that of fresh lime juice.” Holst and Froelich in 1907 carried out a similar but less extensive investigation. They also found that lime juice was unable to protect guinea-pigs from scurvy. Fuerst, a co-worker of Holst, continued this work, and in his article of 1912 stated that guinea-pigs should not be protected by a daily addition to their ration of 25 g. of lime juice; these guinea-pigs received a mixed diet consisting of dry vegetables, butter, almonds and malt extract. These two reports of the Norwegian investigators on this interesting subject should have attracted attention.

Other Fruits.—A word may be said in regard to some other fruits. The antiscorbutic potency of raspberries was tested by Holst and Froelich (1912) and found comparable to oranges and to lemons. The juice was also highly resistant to heat, so that 10 c.c. of freshly-pressed juice were of protective value, even after it had been subjected to 100 or 110° C. for one hour. Guinea-pigs which were thus treated showed no microscopic signs of scurvy in any of the ribs, in the tibiÆ or the femora.

TABLE 3

These authors also reported that they found banana and apple poor in antiscorbutic power, 30 g. daily being insufficient to protect a guinea-pig (Table 3). This was our experience with banana in the treatment of infants suffering from mild scurvy. The banana has been shown by Sugiura and Benedict to be poor also in the water-soluble vitamine. It would be of interest to determine the difference in vitamine content between the fully ripe and the unripe fruit.

In view of the fact that grapes are used considerably in the treatment of infantile scurvy, it is of importance to realize that they are poor in the antiscorbutic principle. Chick and Rhodes found that three of four guinea-pigs receiving 20 g. daily developed scurvy; they rated the potency as ten times less than that of orange juice.

It is everyday knowledge that fresh vegetables are of great value in the protection from, and cure of, scurvy. The first experimental investigation of this subject was that of Holst and Froelich, published in 1907, and continued in a series of papers extending to 1916. These investigators tested the potency of a large number of vegetables by feeding them in varying quantities to guinea-pigs. They found that all vegetables have antiscorbutic value but to a markedly varying degree. Cabbage, sorrel leaves, endive, head salad, and dandelion leaves, were found to be of most avail in protecting against scurvy, whereas carrots, cooked potatoes and cooked turnips, and cauliflower proved to be of less value. In general, it may be stated that the leafy vegetables have more antiscorbutic power than the roots or the tubers. This generalization, we shall see, is not without exception, e.g., the swede. Similar experimental work has been recently carried on by a group of investigators at the Lister Institute, who have added considerably to our knowledge in this field. In all this experimental work cabbage has been found to be the most potent of the vegetables, and therefore experiments have centered about it just as in considering fruits the work has centered about orange juice or lemon juice. We shall, therefore, discuss in detail its reaction to heat and dehydration.

Cabbage.—Holst and Froelich found that 1 g. daily of fresh cabbage afforded nearly complete protection to guinea-pigs, and Delf has corroborated this work. This amount is sufficient to prevent the development of manifest scurvy, although it does not induce satisfactory growth. In this respect it is comparable to giving 1.5 c.c. of orange juice daily. If guinea-pigs take only 0.5 g. of raw cabbage, scurvy will develop; whereas 2 g. or more will promote satisfactory growth and no scorbutic changes will be found on microscopic examination.

Effect of Heating.—Vegetables are of decidedly less antiscorbutic value when cooked than raw; cabbage, for instance, on being boiled is weakened about one-half. Heating to 110° C. for an hour destroys almost all of its antiscorbutic factor. Delf’s tests did not show so great a loss. She came to the conclusion, of theoretical and practical value, that slow cooking at a low temperature is much more deleterious than rapid cooking at a higher temperature. Hess and Unger found that carrots lost much of their antiscorbutic power after boiling, and that this was the result of a true destruction, the vitamine not having been merely dissolved in the water of boiling; for if guinea-pigs consumed 40 c.c. per capita of this water, they were not protected against scurvy (Fig. 11). Acidulating the water with 10 per cent. vinegar did not reduce the loss, an experience similar to that of others using citric acid or lemon juice.

Vegetables cannot be considered from an antiscorbutic standpoint as a standard and uniform foodstuff, as they vary in their content of this factor according to their freshness and age. This was demonstrated by means of feeding experiments with carrots. For example, 35 g. of old carrots, such as were used for feeding the laboratory animals, afforded but little protection after having been cooked in an open vessel for about 45 minutes, whereas the same amount of young carrots cooked this way protected the guinea-pigs. It is obvious that this distinction is of importance in evaluating the antiscorbutic content of the various foods, and in considering whether individuals and groups of individuals are receiving an adequate quota of antiscorbutic vitamine. It will be noted later that it is also of importance in connection with the potency of dehydrated vegetables. Recent experiments indicate that not only age, but the degree of ripeness must be considered in appraising the food value of vegetables. Feeding experiments showed that tomatoes which were fully ripe were more potent than those which were slightly green. Probably many other factors play a rÔle in determining the richness of vegetables in vitamine. It may not be immaterial whether they are allowed to ripen on the vine or shrub, or mature subsequently. The nature of the soil may also affect the antiscorbutic quality of the vegetables or fruit. So that it is evident that we must not be schematic in considering this question, and must realize that a table of antiscorbutic values, such as accompanies this text (Table 3), does not furnish definite and inflexible values.

There is a marked difference between vegetables and vegetable juices in keeping quality, and in their reaction to heat and to acid. In general, it may be stated that the juices are much more sensitive. Holst and Froelich brought out this point in 1912 and enlarged upon it in their publication of 1916. The different juices vary greatly in this respect; for example, dandelion juice is acutely sensitive to heat, whereas sorrel leaves withstand high temperatures very well. In regard to these differences an analogy may be drawn to the fruit juices. Lemon, orange and raspberry juices are markedly thermostable, but lime juice is weakened markedly by heat. Many of these juices are protected by the addition of acid—5 per cent. of lemon juice increasing the thermostability of cabbage juice—whereas, as we have stated, little is gained by cooking vegetables in an acid medium.

Potato.—The civilized world is dependent for its quota of antiscorbutic foodstuff largely upon the potato. It might be thought, therefore, that this would signify that the potato is endowed with great antiscorbutic power. Such is not the case, however, as demonstrated both by laboratory tests and clinical experience. Considering its importance, there have been surprisingly few feeding experiments carried out with potato. Holst and Froelich (1912) found that 17 g. of potatoes, steamed at 100° C. for 30 minutes, afforded but slight protection, and that it required 20 g. to fully protect a guinea-pig. Givens and Cohen failed to ward off scurvy by means of cooked potatoes fed to the equivalent of 5 g. of the raw vegetable (guinea-pigs will not eat raw potatoes). There are no accurate figures as to the quantity of potatoes needed to protect a human being from scurvy. The statement of Doctor Guy, however, who after careful study of convicts’ diets, concluded that 14 ounces daily would protect them from scurvy (if the ration included one ounce of other fresh vegetable and 4 ounces of meat), is probably close to the mark.41 With the experience that potatoes play such a significant rÔle in the prevention of scurvy, how are we to interpret the fact that they are only mildly antiscorbutic? Potatoes are consumed in very large amounts; in the Temperate Zone probably twice as many pounds of potatoes are consumed during the winter as of all other vegetables combined (Fig. 1). It is evident, therefore, that in a practical evaluation of antiscorbutic foodstuffs, not only the intrinsic antiscorbutic potency must be considered, but also the quantity of the vegetable or fruit consumed.

Swede.—We cannot leave the consideration of vegetable antiscorbutics without adding a few words as to the value of swede juice,42 which has been recently highly recommended by Chick and Rhodes, who found it comparable to the cabbage and the onion, and even to orange juice. For example, 25 c.c. of raw swede juice were equivalent to 1.5 g. of raw cabbage. It is, therefore, more potent than the juice of raw carrot, and far more efficacious than the juice of the beetroot (Table 3). Tests carried out with this antiscorbutic in infant feeding seemed to show that it is of value in this field. The authors believe that the potency of vegetables is closely associated with certain botanical species, and that in this way the marked virtue of the swede can be explained, as it belongs to the natural order of CruciferÆ, which includes also the cabbage, the scurvy grass and the cresses. If, however, this is a rule of nature, it is difficult to explain the marked difference between the lime and the lemon, which are both varieties of Citrus Medica.

Dehydrated Vegetables.—For hundreds of years fresh vegetables have been dried to serve as food during the winter months and have fulfilled a useful purpose on account of their small bulk and great food value. The question for us to consider, however, is whether dehydrated vegetables still retain their antiscorbutic quality and can be counted on to supply this factor in the dietary. At present this subject is engaging the attention of laboratory workers as well as of practical dietitians and food hygienists. The experience of the past is not happy in this regard. In the Medical and Surgical History of the War of the Rebellion we read as follows: “A scorbutic tendency was developed at most of our military posts during the winter season, after the troops had been confined to the use of the ordinary ration with desiccated vegetables. The latter in quantities failed to repress the disease.” In spite of this and similar military experiences43 the employment of dehydrated vegetables was urged recently for rationing our soldiers, the claim being made that “by simply soaking in water and boiling in the same water these vegetables are brought back to the condition of fresh vegetables.” Both in this country and in England there was strong propaganda during the war to dehydrate vegetables on an enormous scale and to substitute them for the fresh food.

Experimental investigation on this subject may be summarized as showing that vegetables dried according to present methods lose their antiscorbutic value as the result of dehydrating (Fig. 12), and that they become still more impoverished as the result of aging. We should not sweepingly condemn the principle of dehydration, as very possibly some slight modifications in the process may be devised which will counteract the deteriorating influence. In their paper of 1912, to which reference has been made so often, Holst and Froelich reported that potatoes, carrots, peas, lentils and almonds have practically no protective value after they are thoroughly dried. In two reports—one giving the results of feeding various brands of dehydrated carrots to guinea-pigs, and the other of an attempt to cure scurvy in babies by means of these carrots—we also came to the conclusion that the antiscorbutic factor had been almost completely destroyed. Givens and Cohen (1918) found that even cabbage dried at a low temperature retained only a small amount of its potency after a month, and Delf and Skelton came to practically the same conclusion, also noting that the cabbage on being kept, steadily lost what little of the antiscorbutic factor had survived the drying process. The same was true of the fat-soluble factor. These authors made an observation which may prove of value in helping to solve this problem, namely, that “the residual amount is distinctly greater if the cabbage is plunged into boiling water before drying.” This protective action of heat they suggest may indicate that: “Some at least of the destruction may be due to the activity of an enzyme or other body originally present in the living tissue.”

Another observation which may prove of practical value in rendering dehydrated vegetables the nutritional equivalent of the fresh vegetable is that when the carrots selected for dehydration are young and fresh a product is obtained which possesses decided antiscorbutic power. In this connection the following statement by Falk and his co-workers in a study of the enzyme action of vegetables and the effect of dehydration is significant: “In considering these enzyme results, it may be pointed out that the state of ripeness and the age of the vegetable undoubtedly influence the activities.”

The most promising dehydration experiment has been conducted by Holst and Froelich and was published in 1916 in a paper which has passed unnoticed. They dried white cabbage so that it retained its antiscorbutic properties, and, to a large extent, its color and taste, for a period of two years. This result was accomplished by keeping out all moisture and preventing hydrolysis,44 a method which is employed in preserving antitoxins, toxins and agglutinins. It is by far the most encouraging test reported, and should be made the basis of further work by those actively interested in perfecting dehydration.

Canned Food (Tomatoes).—In the course of canning, as in dehydrating, most vegetables and fruits lose their antiscorbutic properties. A general denunciation, however, of all canned foods is incorrect, as there are exceptions to this rule. It has been shown by Hess and Unger that canned tomatoes possess a high degree of antiscorbutic power (Fig. 13), and it is probable that most of the acid fruits and vegetables are able to withstand the canning process. It was found, in an experiment embracing many series of guinea-pigs, that 4 c.c. daily of strained, canned tomato are sufficient to afford protection, even when a lot was used which had been prepared a year previously. This is indeed remarkable, considering that the food undergoes a two-fold heating in the course of canning, during one of which (“processing”) the temperature is raised to fully 230° F. Tomatoes have another advantage over most other vegetables in that they are richly endowed with the water-soluble vitamine, as shown by our tests on pigeons suffering from polyneuritis, and by the experiments on rats of Osborne and Mendel, who found tomatoes far superior in this respect to turnips, onions, beetroots or beans. They are also rich in the fat-soluble vitamine. In view of the availability of canned tomatoes and their excellent keeping quality they are well suited to an extended use as an antiscorbutic. In the subsequent chapter we shall discuss their employment in infant feeding and in the army ration.

Germinated Cereals and Pulses.—In 1912 Fuerst reported that although the resting seed—the cereal grain, the pea, bean and lentil—are poor in antiscorbutic vitamine, they develop this principle as soon as they germinate. They possess, in other words, latent antiscorbutic properties, and are potentially antiscorbutic. This observation is not only of scientific interest but of practical value, as these pulses are well suited for transport and do not readily deteriorate. For this reason, Chick and her co-workers at the Lister Institute, who were searching for an antiscorbutic foodstuff for the army, directed their attention to the utilization of the pulses. In the course of a thorough investigation (1919) they found that although it required 30 to 40 g. daily of dry green peas to prevent scurvy in the guinea-pig, a consumption of 10 g. of the germinated peas afforded satisfactory protection.45 The soaked seeds have an antiscorbutic value comparable to many of the fresh vegetables; by no means as great as cabbage, but somewhat greater than that of carrots. As the result of cooking, their potency was found to be reduced about 75 per cent. We shall have occasion to refer to this antiscorbutic food in the chapter on treatment in connection with the rationing of armies.

Meat and Eggs.—As has been stated, animal tissues are distinctly inferior to fruits and vegetables in the antiscorbutic principle. As there has been no accurate evaluation of these foods—the only test being one by Chick, Hume and Skelton, where 10 c.c. of raw beef juice failed to protect guinea-pigs—we have to depend upon clinical experience for our knowledge. Beef juice is highly rated by physicians in the prevention of infantile scurvy, but it is probably far less potent than vegetables or fruit juices. The Arctic explorers, and many who have lived in the Arctic regions, agree that the inhabitants are protected from scurvy during the winter months by their diet of fresh meat and fish. The Admiralty Enquiry on the outbreak of scurvy in the Arctic Expedition of 1875 reported that a large ration of meat is necessary to afford protection. Curran (1847) described three cases admitted to the hospital in the great Irish epidemic of that year, where the diet previously had included three-quarters of a pound of meat on five days of the week. From these and similar experiences the conclusion is manifest that the divergence of opinion regarding the value of meat is based upon quantitative differences in the rations. Evidently, if sufficient meat is provided, the development of scurvy will be obviated. Another factor which must be borne in mind is that those who refer to meat in the Arctic regions refer to fresh raw meat, which is a far more valuable antiscorbutic than the ordinary cooked meat.

There is almost no experimental data on the antiscorbutic value of eggs. Hard-boiled eggs were fed to guinea-pigs and it was found that 9 g. per capita daily was insufficient to protect them. An attempt was also made to cure infantile scurvy with a daily addition of one raw egg to the dietary, but without avail. It is possible that fresh raw eggs have an antiscorbutic value comparable to meat, but the large quantity required makes dependence upon them impracticable.

Beer and Alcoholic Beverages.—For generations beer has been highly regarded as an antiscorbutic. Captain Cook prized it greatly and always supplied his men with a freshly-made infusion of malt called “sweetwort.” Lind writes: “Beer and fermented liquors of any sort will be found the best antiscorbutic remedies” (p. 76). He refers at different times to the value of spruce beer, ale, wine and other vinous liquors. In his excellent book on “Military Hygiene,” Munson writes: “Good beer and wine have decided value, also vinegar.” On the other hand, recent scientific experiment has shown that beer has practically no antiscorbutic value. There is but one study on this subject, that of Harden and Zilva, which is quite convincing. They found that guinea-pigs and monkeys developed scurvy in spite of the fact that they received, respectively, 50 c.c. and 180 c.c. of beer daily. They conclude, as a result of their experiments, that “bottled ale and stout and fined beer as brought on to the market, are lacking both in antineuritic and antiscorbutic accessory factors, and that kilned material is also wanting in these two principles.” The apparent contradiction between practical experience and laboratory investigation in regard to beer is due to a difference in the process of brewing. Cook and Lind and the older authors refer to freshly-made beer, whereas the modern beer which was tested in the laboratory was made from “high-dried” material. The antiscorbutic potency of beer as formerly used was due to its preparation from freshly-germinated grain and its consumption shortly after brewing. Dyke tells us of an interesting incident illustrating the importance of this distinction. In the recent war an outbreak of scurvy occurred among the Kaffir labor battalion in France. At home these natives consume a large amount, as much as three gallons a day, of Kaffir beer, which is made from freshly-germinated corn, and is consumed shortly after it is made. The French prepared a similar fermented beverage for their South African laborers, the sole difference in preparation being that the process of germination had been omitted for reasons of convenience. Scurvy resulted, a disorder which is practically unknown among the natives at home.

Miscellaneous Foodstuffs.—During the past few years a great many different kinds of foods have been tested in the laboratory for their antiscorbutic value. It will be well for completeness’ sake to say a word about them, although they have been found to possess little or no antiscorbutic properties. The studies of Holst and Froelich showed definitely that all the cereals—oat, barley, rye, maize, and preparations made from the bran or from the endosperm—are devoid of antiscorbutic vitamine. Cohen and Mendel added 3 per cent. of calcium lactate or sodium chloride, or 5 per cent. of butter, without enhancing the value of oats in this respect.

As is well known, yeast possesses the water-soluble vitamine in marked concentration. It is natural, therefore, that its antiscorbutic power was put to the test, especially as it has been accorded therapeutic value. Hess and Unger showed that autolyzed yeast was of no value in the cure of infantile scurvy (Fig. 14); Chick and Hume (1917) and Cohen and Mendel (1918) came to the same conclusion in regard to guinea-pig scurvy, making use of autolyzed yeast, yeast extract and dried brewers’ yeast.

In view of the fact that cod liver oil is practically a specific for human rickets, Hess and Unger tried the effect of this oil both in infantile scurvy and in that of guinea-pigs. It proved to have no protective or curative value. The animal experiments were confirmed by Cohen and Mendel. The use of olive oil also proved futile.

Pitz in 1918 reported that in animal experiments he had found that lactose was able to protect against scurvy, and attributed this result to its power to alter the intestinal flora. We shall not enter into a detailed discussion of this question, as the study was carried out on a ration embodying unlimited and uncontrolled amounts of milk, and it has since been shown that the apparent cure was due to an increased consumption of milk by the animals in the progress of the experiment. Cohen and Mendel, Harden and Zilva, Hart, Steenbock and Smith (1919) all failed to protect or to cure their animals with lactose when they were placed on a ration which was definitely measured and limited. Hess and Unger failed to cure infantile scurvy by means of lactose.

It has been suggested that scurvy is due to a lack of secretion of the endocrine glands, a question which will be referred to again in considering the relation of scurvy to other “deficiency diseases.” With this idea Ingier added thyroid, hypophysis, thymus and parathyroid to the food of guinea-pigs, or gave it parenterally. She was unable to observe any beneficial results. Jackson and Moore met with the same result on feeding desiccated thyroid gland. We may add that we gave dried thyroid and also parathyroid glands in the treatment of infantile scurvy without effect.

CONCLUSIONS

Any consideration of the question of antiscorbutic foodstuffs brings into sharp relief the difference between empiricism and scientific investigation. For well over a hundred years it was generally known that scurvy could be cured by fruits or vegetables, and yet no further progress was made toward a more complete understanding of the value of these foodstuffs. As far back as 1847 Budd ascribed the action of antiscorbutic foods “to an essential element, which, it is hardly too sanguine to state, will be discovered by organic chemistry or the experiments of physiologists in a not far distant future.” Busk, in giving his testimony in 1877 before the British Scurvy Commission, said that it was his belief “that scurvy was due to the fact that the diet was lacking in a peculiar and as yet little-understood factor.” The question remained in this hypothetical and inactive state until it was attacked recently by experimental methods. Decided advance has been made only in the past few years, since these foodstuffs have been studied from a quantitative viewpoint.

The antiscorbutic factor is abundant in fresh foods, especially in vegetables and fruits, and to a considerably less extent in animal foods, such as milk, meat and fish. Among the vegetables there is a marked distinction in potency. A beginning has been made in standardizing these various foodstuffs, in grading them approximately according to their antiscorbutic efficacy (Table 3). It should be remembered, however, that the importance of an antiscorbutic food depends not only on its intrinsic content of the antiscorbutic factor, but quite as much on the amount of the food which is eaten. For example, although potatoes possess only moderate virtue compared with orange juice, they are of greater practical value in view of the large quantities which are consumed and their availability when green vegetables are lacking. Furthermore, the fact recently brought out that the various vegetables, and perhaps the fruits as well, have considerably more value when they are fresh and young than when they are old, warns us not to carry our quantitative standardization too far.

Fruits and vegetables which are dehydrated have been found to have lost their antiscorbutic properties. This generalization is not without its exception, for it has been found that cabbage and tomato withstand drying well, and that if milk is dried under favorable conditions it retains a very large part of its antiscorbutic value. It may be stated that the outlook is bright in regard to dehydration, as the problem has not yet been thoroughly studied, and the process may be so improved that there will be little difference in the nutritional value between the fresh and the dehydrated food.

The study of antiscorbutic values points a lesson in regard to the methods of cooking vegetables. It has demonstrated that short cooking, associated with a high degree of temperature, is less deleterious than longer cooking at a low degree. In other words, that less damage is brought about by boiling or by steaming vegetables than by stewing them. Here age and freshness again play a rÔle; in fact, a double rÔle, as the older and tougher vegetables contain not only less antiscorbutic, but require more prolonged cooking.

In general, the belief is correct that canning destroys the antiscorbutic value of foods, but once more an exception must be made, for it has been found that acid foods, such as the tomato, withstand the canning process with but little loss of potency.

The field of antiscorbutic foodstuffs is one which is fertile for future investigation. The antiscorbutic status of milk heated to various heights of temperature and subjected to various degrees of aging furnishes problems of great practical importance. A lack of growth has been noted when antiscorbutics are given which have been subjected to a high degree of heat (e.g., autoclaved orange juice). Whether this is due to the destruction of some other growth factor is a question which has been raised by several experimental studies and requires an answer.

It is quite possible that we shall find useful antiscorbutic foods which at present are unknown or unappreciated. The recent introduction of the swede, of the canned tomato and of germinated pulses suggests and even renders this probable. On the other hand, the recognition of the comparative poverty of the antiscorbutic factor in lime juice shows the importance of putting each foodstuff to the experimental test.