Though this work has already been carried to a great length, I hope those of my readers, who may have done me the honor to go attentively through the whole of it, will pardon me the addition of a few incidental thoughts and queries. The chain of arts is so well connected, that researches originally intended for the illustration of any one of them, can hardly fail of throwing some light upon others.

1. The seed of plants cannot be put in a fitter place, for perfect vegetation, than when buried under ground, at a depth sufficient to defend the young shoots from the vicissitudes of heat and cold, and the disadvantage of too much moisture. The manuring of the earth, and the steeping the seed into solutions of salts, have been found, in some cases, to increase the strength of the grain, to correct its original defects, and to prevent the noxious impressions of a vicious ground. Plants are made to germinate in water alone, and this experiment so successfully carried on every winter, in warm apartments, may still be improved by dissolving salts in the water.—Could the barley used for malting be put in the ground, its growth would be more natural, and its oils becoming more miscible with water, by the saline nourishment derived from the earth, might yield more vinous, more strong, and more lasting liquors. But as this method is impracticable, would it be impossible to increase the efficacy of that which is used? Consult Home on agriculture: might not either nitre or salt petre be added to the water, with which the grain is moistened? are they not used with success to manure land? Are not solutions of them in water employed by the farmer to steep his sowing seed? I barely mention these as some of the substances, that might be employed in the malting of barley, and am far from thinking there are none other. Perhaps different salts should be used, according to the nature of the soil, from which the corn was produced; but a variety of experiments seems to be required, in order to discover how far art might in this case imitate and improve nature.

2. A small quantity of malt, at all times, but especially when brewed in large vessels, parts too readily with the heat which extraction requires; and, on the contrary, if the quantity of malt be very great, the heat may not be uniformly spread. A forward beer inclinable to acidity is often the result of too short a grist; a thick, stubborn, and rank liquor many times is produced from too large a one. Every advantage may be had in brewing, properly, five or six quarters of malt; it is difficult to succeed if the number exceeds fifty.

3. The strong pungent volatile spirit, which exhales from a must, when under full fermentation, has been supposed to be a loss, which might be prevented; and accordingly attempts have been made to retain these flying impetuous particles, by stopping the communication between the atmosphere and the fermenting drink. That there is a dispersion of spirits is beyond doubt, and that these exhaling vapors consist of the finest oils, which the heat forces out of the must, is equally certain. But this loss seems to be abundantly repaid by the stronger oils, which the same degree of heat attenuates and substitutes, in a larger quantity, to the former. The last oils could never come under the form of a vinous liquor, but by a power, which sooner or later dissipates some of the first. Pale ales or amber not only lay, for many days, exposed to the open air, but suffer, by the periodical renewal of the action of the air, every two or four hours, a much more considerable loss of spirits, than when fermentation is carried on uniformly. Yet experience shews, that so many oils are, by this method, attenuated, that the strength acquired greatly surpasses that which is lost.

4. The practice of fermenting by compression, recommended to distillers, seems, on this account, less useful, than might be concluded from theory alone; the intent of the distiller, as well as of the brewer, is to extract the greatest quantity of spiritous oils. It is impossible to ferment a must in vacuo; air is absolutely necessary to carry on this operation, even a superabundant quantity of oils admitted into the must, by obstructing the free admission of the air, impedes fermentation, prevents the wine from reaching pellucidity, and sometimes is the occasion of its becoming putrid.

5. When the purest spirit is intended to be drawn from the grain, the fermented wash ought to be suffered to settle, till it becomes transparent. The dispatch, with which the distillery is generally carried on, often prevents this useful circumstance taking place, and occasions a want of vinosity in the liquor. In many cases, the extraordinary charges of extracting the grist from malted corn, in the manner, which has been directed for drinks intended a short space to be kept, and of suffering the fermented wash to be meliorated by time, until it becomes vinous and spontaneously transparent, might be abundantly repaid. Yet, if hurry must be a part of the distiller’s business, he should at least make such extractions as admit of the speediest fermentation and the readiest pellucidity. He cannot expect corn spirits to equal the brandies of France, unless his worts are similar to the wines distilled in that kingdom, where those used for this purpose are weak, fine, and tending to acidity.42 He would therefore secure to himself the greatest probability of success, if he employed only malted corn in his grist, this of the best kind, well germinated to form a saccharine basis, slack dried, and resolved, with weak extracts, to preserve into the must a proper proportion of vinosity. If he intended this wash to be formed into a pure spirit, it should be allowed time to become transparent; he might regulate his extracts by such heats as have been fixed for common small beer, brewed when the heat of the air is at the lowest fermentable degree, though perhaps heats less than these, when dispatch is required, might better answer his purpose, especially as the length used in the distillery is nearly the same with that which brewers use for the liquor here referred to. With hot waters to attempt to force from the grain more strength or more oils, than such as will form a clean tasteless spirit, is, in the distillery, a real loss and a fundamental error. By too strong heats, more oils are forced into the must than can be converted in spirits; and fermentation being, by this over charge, in some measure, clogged and impeded, a less yield is made, and the liquor obtained of a rank and often empyreumatic taste.

6. Why are the brandies of Spain inferior to those prepared in France? The wines of the last country are the growth of a weaker sun; they contain no more oils than can be assimilated by fermentation, and form a clean, dry, nutty spirit. The Spanish wines abounding with more oleaginous than acid parts, this over proportion becomes not only useless, but hurtful in the still, and produces the rankness observed in Spanish brandies. The cleanness of the spirit arises, in great measure, from the weakness of the must, and its vinosity from a less proportion of oils to the salts. This seems to be the reason why the most grateful spirits are produced from wines unable to bear the sea, or to be long kept.

7. The native spirits of vegetables, says Boerhaave, are separated by heats between 94 degrees, and 212. To obtain the whole of these, the fire must be gradually increased; for a superior heat dissipates the spirits raised by an inferior one. Such parts as might be obtained by 100 degrees, are lost if the heat applied be much greater. It is true, the parts of vegetables immersed in water, cannot so easily be dissipated as if they were in open air, yet, by the rarefaction of the liquid, a proportional evaporation, however small, must ensue, or the oils raised by a greater heat may so effectually envelope the finer ones, as to make them hardly perceptible either to our smell or taste. Thus, though heated water is able to extract all the virtues residing in the vegetables, the different application of the fire will alter not only their proportions, but their properties also, when we consider that pure spirit of wine boils at so low a heat as 175 degrees. If the above principles be true, that surely must be the cleanest spirit which is brought over in the slowest and coolest manner; and it is more than probable, if the rules here laid down be put in practice, the grain of England will be found to yield spirits that may vie with the brandies of France, be more pure than those of the Indies, and excel those of Holland.

8. The vinegar maker is equally concerned with the distiller in the brewing process. Vinegar is produced in the last stage of fermentation, when a gross, tartareous, unctous matter, consisting of the coarser oils extracted either from the grain or the grapes, generally falls to the bottom of the liquor, and no longer prevents its acidity, or affects its flavor. Though the best vinegar proceeds either from the strongest wines or beers, this strength consists in the quantity of fermentable principles, and not in that of mere oleaginous parts. By properly adapting the extracting waters, this hurtful impediment may be removed, and the vinegar from malt liquors become as neat and as strong as that which is made from wine.

9. As the acid taste of vinegar is the effect of a continued fermentation, many people have thought it immaterial how speedily the first parts of the operation were carried on. But violent fermentations not only dissipate some of the fine oils, which should be retained in the vinegar, but also cause the must to tend towards putrefaction. Boerhaave, after he has directed a frequent transvasion of the liquor, observes that, whenever the weather or the workhouse is very hot, it is often necessary to fill the half emptied vessels every twelve hours, not only to procure a supply of acids from the air, but also to cool the wine, and check the too violent fermentation, which arising in the half full casks, might dissipate the volatile spirits, before they are properly secured and entangled by the acid. Hence the liquor might be sour indeed, but at the same time flat, and would never become a sharp and strong vinegar.

10. Application and uses have frequently been found for materials, which before were supposed to be of no value. The grains, after the brewer has drawn his worts out of them, are generally used for the feeding of cattle; but I do not know that hops, after boiling, have been employed to any purpose. Is there nothing more left in this vegetable, after it has imparted the virtue wanted to the beer? All plants burnt in open air yield alkaline salts, though in a greater or less quantity, according to the quality of the plants. Boerhaave says that those which are austere, acid, or aromatic, yield in their ashes a great abundance of salts, and these being put in fusion, and mixed with flint or sand, run into glass. Hops thrown, after decoction, in no great quantity on the fire, cause the coals to vitrify, or as it is generally termed, to run into clinkers. If therefore the remains of the hops were burnt in open air, or in a proper furnace, it seems most likely that no inconsiderable quantity of somewhat like pot ashes might be obtained, and this, considering the many tun weight of hops employed in large cities, and thrown away as useless, might become an object of private emolument to the brewer, and of public benefit to the kingdom.

FINIS.