43 METABOLIC EQUILIBRIUM. 



various carbohydrates, especially starch. Alcoholic fermentation is a result 

 of the vital activity of a low order of fungus, namely the yeast-fungus the sac- 

 charomyces cerevisiae (in the fermentation of beer) and the saccharomyces ellip- 

 soideus (in the fermentation of wine), the fungus removing directly from the 

 saccaharine mixture the substances necessary for its existence, namely carbo- 

 hydrates, albuminates and salts, chiefly calcium phosphate, potassium phosphate 

 and magnesium sulphate and causing their decomposition into alcohol and car- 

 bon dioxid, together with some glycerin (from 3.2 to 3.6 per cent.) and succinic 

 acid (from 0.6 to 0.7 per cent.)- The yeast-liquor alone, in the absence of yeast- 

 cells, also causes fermentation, through the presence of a ferment known as zymase, 

 which acts like a chemical agent. Yeast belongs to the budding fungi, which 

 multiply both by budding and by sporulation (ascospores) . It is added directly 

 to the fluids to be fermented, or its spores, which constantly float about in the air, 

 fall into the uncovered mixture. Perfect exclusion of yeast-cells, or their destruc- 

 tion, as by boiling the syrup in sealed vessels, therefore, prevents the occurrence 

 of fermentation. Alcoholic fermentation is, therefore, a result of the vital activity 

 of a lower form of organism. 



Wine contains on an average from 89 to 90 per cent, of water, from 7 to 8 

 per cent, of alcohol, together with the ethyl-alcohol, propyl-alcohol and butyl- 

 alcohol. The color of red wine is derived from the skins during fermentation. 

 If the skins be previously removed red grapes will yield whitish wine. The fine 

 taste (flower, bouquet) develops during the storing of the wine. Enanthic ether 

 is said to give rise to the characteristic odor of wine. The value of wine depends 

 upon the as yet unknown stimulating, volatile substances that confer upon each 

 wine its special character. Of great importance are, further, the salts, which in 

 their composition resemble those of the blood. 



Beer contains from 75 to 95 per cent, of water, alcohol from 2 to 5 per cent, 

 (porter and ale as much as 8 per cent.), carbon dioxid from o.i to 0.8 per cent., 

 sugar from 2 to 8 per cent., gum, dextrin from 2 to 10 per cent., cholin, the con- 

 stituents of hops, some residue of protein-substances (gluten), fat, lactic acid, 

 ammonia-compounds, the salts of barley and of hops. 



In the ash the enormous amount of phosphoric acid and potassium carbon- 

 ate, so important in the formation of blood, is noteworthy; one hundred parts of 

 ash contain of potassium carbonate 40.8, phosphorus 20, magnesium phosphate 

 20, calcium phosphate 2.6, silica 16.6 per cent. The favorable influence of beer 

 on the formation of blood, muscles and other tissues is due to the abundance of 

 phosphoric acid and potassium carbonate. The obesity of the beer-drinker de- 

 pends chiefly on the fat-sparing action of the alcohol. The potassium carbonate 

 present in beer has a fatiguing effect after heavy drinking. 



Spices are not consumed because of their nutritive value, but in part on account 

 of their taste, in part because of their stimulating effect, through which they arouse 

 the digestive organs to increased activity. In a certain sense sodium chlorid 

 must also be regarded as a spice, being withheld at present apparently from only 

 a few savage tribes. A similar fact was recorded by Homer. Also certain as 

 yet unknown substances that have a marked effect on the organs of taste, and 

 that develop only in the course of preparation of some dishes, as in the crust 

 of a roast, and in the crust of pastry, may be included among spices. 



PHENOMENA AND LAWS OF METABOLISM. 



METABOLIC EQUILIBRIUM. 



By metabolic equilibrium is understood that normal condition in 

 which precisely the same amount of material for the maintenance and 

 growth of the organism is taken up and assimilated from the digested 

 nourishment as is removed from the body through the excretory organs 

 in the form of waste-materials or end-products of retrogressive tissue- 

 metamorphosis. The income must always balance the expenditure. 

 During the period of growth of the body a certain excess of formative 

 activity corresponding to the increase in size of the body must pre- 

 dominate. Thus, growing portions of the body exhibit from 2.5 to 6.3 



