Alcohol is a peculiar fluid, produced only during the chemical changes through which the juices of various organic substances pass in the process of vinous fermentation. The product is dependent directly upon a change in the saccharine (sugar) constituents of plants–as starch, gum, and sugar proper. Plants containing no sugar, will not yield any alcohol; and the amount of this product is directly proportionate to the amount of saccharine material contained in the substance acted upon. Sugar alone wilt not undergo this vinous fermentation; but requires to be in a diluted form, and then to be acted upon by a species of organic ferment. When the vegetable substance does not contain sugar absolute, its starchy elements first undergo a low form of fermentation, by which they are converted into a species of grape sugar. This step is termed the saccharine fermentation. This is always the nature of the change when potatoes, rice, corn, and similar grains are used to make alcohol. Grapes contain both the saccharine materials, and the ferment necessary to set up and maintain the fermentation; while in other cases, the ferment is not contained in the plant, but has to be supplied artificially–as when the glucose or diastase of fermenting wheat is mixed with other malts, in the manufacture of whisky from corn, etc. A temperature of between 60 deg. and 90 deg. F., has to be maintained steadily, in order to effect the vinous fermentation; as if it fall below 60 deg., the entire process will be arrested, and if it rise above 90 deg., it will pass into the acetous fermentation, and result in vinegar. A mean temperature of about 75 deg. F., is usually employed. See Wine.
Alcohol is not formed in a free state during this fermentation, but is necessarily combined with water, various coloring matters, the salts of the plants acted upon, and such odorous substances as are peculiar to the article used. From these the alcohol is separated by distillation–its low specific gravity enabling it to pass over into a condensing apparatus, while most of the associated materials remain behind. Simple distillation, however, will not free it entirely from all contamination, and various devices have to be used for this purpose. All the alcohol at present in commerce in this country, is obtained by distillation from the whisky manufactured from corn. This contains a small percentage of an extremely pungent and nauseating oil, known as fusel oil, which gives the distinguishing odor to common whisky. This is still present in all alcohol of less than 90 percent. It is now removed by filtering the whisky through a mixture of charcoal, sand, oyster shells, and boiled wheat; then distilling it at a low heat, and then redistilling it from over a moderate portion of manganic acid. The product thus obtained, is known as deodorized alcohol, and the process is that invented by Mr. Atwood. The common alcohol of commerce is not thus completely deprived of its fusel oil; but is put upon the market after two distillations, (the last one from over a bed of chloride of calcium, or carbonate of potassa, to remove the water,) and a passage through several tubs packed with the above filter. In this case, an almost undetectable trace of fusel oil still remains in the alcohol.
Alcohol may be obtained from any vinous liquid, as from the purest wines–when it is called brandy, and retains its flavoring materials and a considerable portion of its water; from the product of the vinous fermentation of potatoes, in which the quantity of fusel oil is very great. It is in the arrack of rice, the pulque of agave, and the whisky of rye, corn, and barley. The fermentation of molasses yields rum; when barley and rye are malted with hops, and rectified from juniper berries, the product is gin, etc. Ale, beer, and porter also yield a small percentage of alcohol. In all these forms of ardent spirit, the exhilarating and intoxicating element is the alcohol.
As alcohol is presented in commerce, and used in the laboratory of the pharmacein, it contains varying proportions of water. Different nations, in their Pharmacopoeias, adopt different grades of strength as their officinal alcohol; but that of the United States accepts that containing 85 percent of alcohol, and 15 of water, by weight, with the specific gravity .835. At the present time, it is customary to speak of alcohol as the product most nearly devoid of water, or that which usually passes in commerce as absolute alcohol. The following terms in common use, represent the accompanying proportion of alcohol by weight:
- Absolute Alcohol, (of commerce,) 98 p. c., Specif. Grav., .798.
- Alcohol of Pharmacy, 85 p. c., Specif. Grav., .835.
- Proof Spirit, Rectified Spirit, Diluted Alcohol, 49 p. c., Specif. Grav ., .920.
In practice, Diluted Alcohol represents equal measures of absolute alcohol and distilled water.
The physical properties of alcohol are thus concisely summed up by the U. S. Dispensatory: "Alcohol is capable of dissolving a great number of substances, as for example, sulphur and phosphorus in small quantity, iodine and ammonia freely, and potassa, soda, and lithia in the caustic state, but not as carbonates. Among organic substances, it is a solvent of the organic vegetable alkalies, urea, tannic acid, sugar, mannite, camphor, resins, balsams, volatile oils, and soap. It dissolves the fixed oils sparingly, except castor oil, which is abundantly soluble. It acts on most acids, forming ethers with some, and effecting the solution of others. All deliquescent salts are soluble in alcohol, except carbonate of potassa." To this may be added the facts that it will not dissolve starches and gum proper; that all the ethers are preparations from alcohol and various acids, both organic and inorganic in origin; and that it arrests animal and vegetable putrefaction, and preserves organisms indefinitely–at the same time causing shrinkage and consolidation in the fibers. As the percentage of water increases, the solvent and preservative powers diminish; and below 50 percent, this diminution is at a greater ratio than the increase of water.
Pharmaceutical Uses: The effects of alcohol on the human frame, are too well and seriously known to need any description here. The article is not remedial, in any sense of the term, (§74; ) but is an exciting, irritating fluid, that sometimes provokes what appears to be desirable effects, (§70,) but which leaves behind a nervous prostration that at once classes it as baneful(§92.) While the Allopathic and Eclectic physicians prescribe ardent spirits in some of their many forms, and class them as their most reliable and active stimulants; the Physio-Medical practitioner does not accept them among his stimulants, and does not employ them as in any sense of the word curative. The only uses to which alcohol can properly be applied, are as a solvent to that large variety of agents which will not yield a fair portion of their properties to water, and as a preservative addition to numerous pharmaceutical preparations. A very serious question arises, as to whether it is proper to use it at all, even for these purposes, where the preparations containing it are to be administered internally. Without it, many valuable agents could be made to yield only a moderate portion of their virtues; and some could scarcely be used in any other than a solid form. Much would also be lost in convenience of prescription and elegance of preparation. But such a question should not be decided alone by economy or comfort, but by the principles of Therapeutics. If the pharmaceutical use of alcohol is detrimental in prescriptions, then away with it. For several years, I refused to employ it as an ingredient in any preparation; and adopted such forms of administration as answered a far better purpose than I had expected, and satisfied my patients well. Accidentally, I was made aware of the fact that an ardent spirit, when completely saturated with a medicine, exerts no intoxicating power. This I tried upon myself several times, to my full satisfaction; and, though strictly a total abstainer from all such beverages, found that an entire pint of wine saturated with a tonic, exerted no intoxicating impression upon me, whereas two ounces of the same wine would otherwise make me quite dizzy. On these facts, I have since used a moderate portion of alcohol in Pharmacy. But I apprehend that the common customs allow far too much alcohol to the amount of medical agents used, so that the spirituous liquid is by no means completely occupied as a solvent. Should this surmise be found to be correct, physicians should take the proper steps to change these relations in Pharmacy. This can probably be done to the best advantage by using dilute alcohol wherever it is possible; so that water shall be allowed to extract all the virtues it can, and only that which is insoluble in water be left to the alcohol. These remarks apply as well to rectified whisky, brandy, wine, and other alcoholic compounds, as to alcohol alone.
The many cases in which alcohol is employed, will be duly named in the department of Pharmacy. As a solvent menstruum, it is mostly used in treating agents of a strongly resinous character, as podophyllum, jalapa, myrrh, guaiacum, capsicum, etc.; also in solving essential oils and soaps, especially when these are to be used in external applications. It is not probable that any thing is gained beyond flavor, in employing the costly wines and brandies in place of the simpler alcohol; and any diuretic properties that belong to gin distilled from juniper, may be gained to better advantage by the employment of a suitable diuretic. A good flavor of brandy may easily be given to spirits by adding one drachm ( or even less) of acetic ether to a gallon of absolute alcohol, and then diluting it with water to any desired standard. I employ this simple method with much satisfaction, and find it answers quite as good a purpose as the high-priced foreign liquor, (brandy,) which contains but from 45 to 50 percent of alcohol.
Alcohol diffuses remedial impressions even more rapidly than is done by warm water. It also seems inclined to direct relaxants strongly toward muscular structures. (§263.) It also makes stronger impressions upon. the nervous centers. It is not, therefore, a suitable menstruum when there is gastric, intestinal, or cerebral excitement; nor when a general effect is desired from an agent that may also act upon the brain, as with cimicifuga and serpentaria.
Ale, beer, and other malt liquors, are not solvents, and have no place in Pharmacy. They are often prescribed on the assertion that they are nourishing; but the most thorough investigation shows that a thousand gallons of them do not contain two pounds of nourishment.
The Physiomedical Dispensatory, 1869, was written by William Cook, M.D.
It was scanned by Paul Bergner at http://medherb.com