A variety of articles of food, which do not properly come under any of the heads previously treated, have, during the past few years, been found on our markets in an adulterated state. Prominent among these, are the various kinds of canned meats, fruits, and vegetables, which have not unfrequently been the cause of serious cases of illness. This result may be owing to the original bad condition of the goods, or to fermentation having taken place; but, in many instances, the trouble has been traced to the improper methods of canning used, resulting in the contamination of the preserved articles with metallic poisons. The fact that fermentation has occurred is frequently indicated by the external appearance of the head of the can, which, in this case, will be slightly convex, instead of being, as it should be, concave. The metals most often detected in canned goods are lead, tin, and copper. The presence of lead is usually due to the use of an impure grade of tin, known as “terne-plate,” in the manufacture of the cans, or to carelessness in the soldering process. The origin of copper is probably to be found in the methods sometimes practised of heating the goods in vessels made of this metal previous to canning them. The presence of tin results from the action of partially decomposed fruits and vegetables upon the can. Preserved fruits and jellies are sometimes put up in unsealed tin pails or cans, when they almost invariably contain notable amounts of this metal.

Asparagus seems to be especially liable to contamination with metals, doubtless owing to the formation of aspartic acid. As much as half a gramme of tin has been found in a quart can of this vegetable. The use of zinc chloride as a flux in soldering, has, to the writer’s knowledge, occasioned the presence of an appreciable proportion of the salt in canned goods.

Of 109 samples of canned food lately examined by our health officials, 97 contained tin; 39, copper; 4, zinc; and 2 lead. In the analysis of food of this description, the organic matters are first destroyed by heating with oxidising agents, such as a mixture of potassium chlorate and hydrochloric acid. The solution is then evaporated to a small volume. It is next diluted with water, and tested with sulphuretted hydrogen, ammonium sulphide, and the usual reagents.

Messrs. Waller and Martin have made an investigation in regard to the proportion of copper which may be present in various natural grains and vegetables. Their results show that these plants frequently take up a minute quantity of this metal from the soil. The amounts of copper found were as follows:—

The following proportions were detected in canned vegetables:—

Meat extracts, while not subjected to adulteration, have acquired a popular reputation as articles of food which is not always deserved. As stimulants and useful adjuncts to food proper for invalids, the value of these preparations is undoubted. The chemical composition of several of the best known brands, as determined by American and English health officials, is given below:—

The factitious manufacture of jellies has lately excited considerable attention. Many of the more expensive kinds of this article are imitated by mixtures consisting largely of apple jelly.

A brand of spurious currant jelly, which is manufactured in France, and has recently made its appearance on the American market, is prepared from a gelatinous seaweed found in Japan (Arachnoidiscus Japonicus), to which glucose, tartaric acid, and an artificial essence of currants are added, the desired colour being obtained by means of cochineal and Althea roseata. The product is offered for sale at five cents a pound.

The flour employed in the manufacture of the maccaroni and vermicelli commonly met with in our larger cities, is not always of good quality. A more serious form of adulteration consists in the artificial colouring of these preparations. The substances used for this purpose, which have been detected by the public authorities, are turmeric, saffron, and chrome yellow. Meat has been found tinted with aniline red, and Bologna sausages, coated with iron pigments, have occasionally been encountered.

The flavouring syrups used in connection with the popular American beverage, “soda water,” frequently consist almost wholly of glucose and artificial compound ethers. Dr. Cyrus Edson, of the New York City Board of Health, has lately directed public notice to the fact that many manufacturers of soda water use water obtained from artesian wells, which are driven on their premises, and which, from the nature of the geological formation of Manhattan Island, are very liable to contain sewage contamination.