474 



ACTION OF ALCOHOL. 



decomposition of the proteids to the extent of 6-7 per cent. Only 

 a very small part of the alcohol is excreted in the urine ; the odour 

 of the breath is not due to alcohol, but to other volatile substances 

 mixed with it, e.g., fusel oil, &c. 2. In small doses it excites, while 

 in large doses it paralyses, the nervous system. By its stimulating 

 qualities it excites to greater action, which, however, is followed by 

 depression. 3. It diminishes the sensation of hunger. 4. It excites 

 the vascular system, accelerates the circulation, so that the muscles 

 and nerves are more active owing to the greater supply of blood. It 

 also gives rise to a subjective feeling of warmth. In large doses, 

 however, it paralyses the vessels, so that they dilate, and tlms much heat 

 is given off ( 213, 7, 227). The action of the heart also becomes 

 affected, the pulse becomes smaller, feebler, and more rapid. In high 

 altitudes, the action of alcohol is greatly diminished, owing to the 

 diminished atmospheric pressure whereby it is rapidly given off from 

 the blood. 



Alcohol in small doses is of great use in conditions of temporary 

 want, and where the food taken is insufficient in quantity. When 

 alcohol is taken regularly, more especially in large doses, it affects the 

 nervous system, and undermines the psychical and corporeal faculties, 

 partly from the action of the impurities which it may contain, such 

 as fusel oil, which has a poisonous effect upon the nervous system, 

 partly by the direct effects, such as catarrh and inflammation of the 

 digestive organs, which it produces, and lastly, by its effect upon the 

 normal metabolism. 



Preparation. Alcoholic drinks are prepared by the fermentation of various 

 carbohydrates, such as sugar derived from starch. The alcoholic fermentation, such 

 as occurs in the manufacture of beer, is caused by the development of the yeast 

 plant, Saccharomycetes cerevisire ; while in the fermentation of the grape (wine), 

 8. ellipsoideus is the species present. The yeast takes the substances necessary 

 for the maintenance of its organic processes directly from the mixture of the 

 sugar viz. , carbohydrates, proteids, and salts, especially calcium and potassium 

 phosphates and magnesium sulphate. These substances undergo decomposition 



1. 



2. 



3. 4. 



Fig. 174. 



1, Isolated yeast cells; 2, 3, yeast cells budding; 4, 5, so-called endogenous 

 formation of cells ; 6, sprouting and formation of buds. 



within the cells of the yeast plant, which multiply during the process, and there 

 are produced alcohol and C0 2 (p. 298), together with glycerine (3"2-3'6 per cent.) 



