powers. The most instructive experiments are those of Dr. Hammond, Surgeon-General of the United States army, who shows that it produces a daily gain of weight, being therefore a useful substitute for deficient food; but being injurious if food be abundant, and the excess not got rid of by increased exercise, &c. He concludes "that alcohol increases the weight of the body by retarding the metamorphosis of the old and promoting the formation of the new tissues, and limiting the consumption of fat."

Those who object to its use, such as Carpenter, argue1. That it precipitates, and does not, like water, dissolve aliments and animal juices; but free dilution and perhaps partly the condition of albumen, as peptone, obviate this. 2. That, as many do not use it, it cannot be necessary. 3. That as a heat-giving agent, it is inferior to fat; some chemists and arctic voyagers assert this. 4. It cannot form azotised tissues or fat. 5. If it stimulates, an equal re-action occurs, so that nothing is gained. It acts as a poison in large doses, and in habitual small ones injures the nervous system, and produces, by a fermentible state of blood, liability to zymotic diseases, and other effects of chronic alcoholism. It is absorbed from the stomach, through the veins passes to the liver, which it often inflames; and it has been destilled as an inflammable fluid from the brain. Ecker states that it is by considerably delaying the cerebral circulation it produces its intoxicating effects. Thein, the active principle of tea, coffee, &c., has physiological effects somewhat similar to alcohol, being also an arrester of metamorphosis. It is stated to be the most highly nitrogenized of vegetable substances by Sir R. Kane (who assigns to it the formula Cg H5 N2 O2 +Aq); yet it is rapidly excreted as urea without fulfilling any plastic office.

II. The Plastic Group includes the albuminoids we obtain from the animal and vegetable kingdoms. From the similarity of flesh used as food to that of the living

body, it is readily assimilated, and thus the more carnivorous the animal, the shorter and more simple is the alimentary canal. The relative amount of nitrogen in various foods, which shows, though not exactly, their relative nutritive power, is given in the following table, milk being taken as a standard of 100:

The heat-giving value of these aliments is nearly the reverse of their flesh-forming. Liebig calculates that if 100 parts of fat produce a certain amount of heat, it will take 240 of starch, 249 cane-sugar, 263 grape-sugar, and 266 of alcohol (50 per cent.) to produce an equal amount. The ultimate composition of blood and flesh is identical; hence it is to be regretted that so much food is lost in the killing of butcher's meat, the blood not being preserved; and meat of a most superior character was obtained by Dr. Carson's plan of killing animals without loss of blood. Flesh from which the alkaline blood is wholly extracted, for instance bled veal, is very unwholesome, as the acids in the muscle then preponderate and is most likely to produce scurvy. I have treated fully of this subject in my "Papers on Public Health, and have suggested some other modes of slaughtering. Vegetarianism is abundantly refuted by the truths of anatomy and physiology; man's teeth, digestive organs, and his habits and circumstances in various climates, clearly showing the necessity for a mixed diet. Many experiments since the time of Haller (despite the example of Shelley and Rousseau, whose main argument was

that both the human species and herbivora had two breasts) have proved the folly of a purely vegetable diet. Among the cases of complete aversion to animal food may be mentioned that of the Abbé de Villedieu, who is said to have died in consequence of having taken some for the first time when 30 years of age. Besides the animals we slaughter, horse-flesh and ass-flesh are now extensively used on the Continent, and Prof. Owen has recommended the introduction of the eland.

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The processes of cooking effect many changes on flesh; that of roasting is the least injurious, as the sudden heat coagulates the surface of the meat, and produces a crust which retains the juices of the flesh. It also converts the fibrous tissue into gelatin, and bursts the fat cells. In boiling meat, Liebig advises that it should be put at once in boiling water, to form a similar coagulated crust, the meat within then closely resembling that roasted. If our object be to make soup, the reverse plan must be adopted-viz., putting the meat in cold water, and then slowly raising the temperature. The strongest extract of beef, or liquor carnis," is obtained by dividing lean meat very minutely, adding but enough of water to moisten the meat, and heating by water placed outside the vessel containing it. A still better soup may be obtained by adding about 12 drops of hydrochloric acid, and about 40 grains of common salt, to the pound of chopped meat, and digesting in about 2 pints of cold water. It must be taken cold, or never heated above 120°, and there is thus introduced a solution of uncoagulated albumen. The uselessness of soups, as ordinarily prepared, should be made known, as much error prevails. They are mostly solutions of gelatin, which substance the French and Dutch "Gelatin Commissions" proved has no plastic and little respiratory value, and is cast off in very considerable quantity in the urine. By boiling meats, much salts are abstracted, and should be restored by the use of vegetables. Their use

lessens the phosphates and increases the carbonates in the blood-hence their influence, as every physician knows, in calculous diseases. They are especially necessary with salted meat, as the potash has been thereby extracted. That flesh should be untainted is shown by the fearful mortality among the Faroese (who eat decomposed food) when they are attacked by measles or other zymotic diseases, and by the poisonous nature of putrid sausages.

The necessity for a Mixed Diet, combining the nitrogenized and unnitrogenized groups, might be premised from the complex nature of the animal body, and is shown by many diseases being produced by the want of any element of food, and by the well-known experiments of Magendie, who fed dogs on sugar, starch, gum, fat, &c., and found they died in about 31 days—indeed almost as soon as if wholly starved. The first part which sloughed was the cornea, as it was the least vascular, yet contained much nitrogen which the food could not supply. Very similar effects were produced in the case of Dr. Stark, who abstained entirely for four months, from nitrogenized food. He was attacked by emaciation and diarrhoea, and sank a victim to his mis-directed physiological zeal. Dr. Budd informs us the Hindus, who feed almost entirely on rice, are often attacked with sloughing of the cornea. Many foods are presented to us by nature, or produced by an art so universal as to be almost natural, in which the various elements of food are duly combined. The egg, milk, and bread, are such perfect alimentary types. In the egg, the yolk containing much fat represents the respiratory class; the white is the type of all plastic food, while water and salts are also present in due proportion. Of milk, and the fat, sugar, casein, water, and salts, contained in it, we shall speak hereafter, and it will be seen that the heat-giving material exceeds, as young animals require and produce abundant warmth.

In Bread, so justly termed "the staff of life," are combined starch, gluten, water, and salts, the oleaginous alone, of all the constituents of food, being absent, but readily supplied by the addition of butter. Bread is of two kinds-1. Vesiculated or spongy, which is superior, mainly by exposing a greater surface for the action of the saliva; and, 2. Unvesiculated or solid, as in the form of biscuit, pudding, and the unleavened bread of Scripture. Vesiculated bread is either fermented or aerated. The former, which has been the staple food of nearly all the world for centuries, is made by mixing the flour with some ferment or catalytic, such as yeast, a substance containing gluten, obtained in brewing. The gluten and starch are both acted on, some of the latter being converted into sugar, and further into carbonic acid gas, which makes the bread light and spongy, and alcohol. The quantity of alcohol produced by panous fermentation is very inconsiderable, yet a bread-making company was started in London, which proposed to collect it. How unpopular this became was shown by the announcement in many shop windows of "Bread sold here with the gin in it." The bread was dry and tasteless, and the project failed. Lime water has been proposed by Liebig in bread-making, as it preserves the tenacity of the gluten. It has been stated untruly that a large proportion of the starch is wasted in making bread by fermentation.

Aerated bread is made by forcing carbonic acid into it, either by mixing carbonate of soda with the flour, and wetting this with water containing hydrochloric acid; carbonic acid is thus evolved, and common salt retained in the bread-or by Dr. Dauglish's process, which is as follows: the flour is wetted by water saturated with carbonic acid in the same way as soda-water; the dough thus made is moulded in tin cases, and the carbonic acid, driven off by heat, renders the bread spongy. The whole process is conducted by steam, and