ACTION OF ALCOHOL. 353, 



effects and agreeable qualities, which are exerted partly upon the organ of taste and partly upon 

 the nervous system. These are called condiments. 



Coffee, Tea, and Chocolate are prepared as infusions of certain vegetables [the first of the roasted 

 berry, the second of the leaves, and the third of the seeds]. Their chief active ingredients are re- 

 spectively caffein, thein (C 8 H 10 N 4 O 2 + H. 2 O), and theobromin (C 7 H s N 4 2 ), which are regarded as 

 alkaloids of the vegetable bases, and which have recently been prepared artificially from xanthin 

 {E. Fischer). [Guarana, or Brazilian cocoa, is made of the seeds ground into a paste in the 

 form of a sausage. Mate or Paraguay tea (the leaves of a species of holly) is used in South 

 America, and so also is the coca of the Andes (Erythroxylon Coca).] These "alkaloids" occur 

 as such in the plants containing them ; they behave like ammonia ; they have an alkaline 

 reaction, and form crystalline salts with acids. All these vegetable bases act upon the nervous 

 system ; some more feebly (as the above), others more powerfully (quinine); some stimulate 

 powerfully, or completely paralyse (morphia, atropin, strychnin, curarin, nicotin). 



Effects. All these substances act on the nervous system ; they quicken thought, 

 accelerate movement, and stir one to greater activity. In these respects they 

 resemble the stimulating extractives of beef-tea. Coffee contains about J per cent, 

 of caffein, part of which only is liberated by the act of roasting. Tea has 6 per 

 cent, of thein ; whilst green tea contains 1 per cent, ethereal oil, and black tea \ 

 per cent.; in green tea there is 18 per cent., in black 15 per cent, tannin; green 

 tea yields about 46 per cent., and the black scarcely 30 per cent, of extract. The 

 inorganic salts present are also of importance; tea contains 3*03 per cent, of 

 salts, and amongst these are soluble compounds of iron, manganese, and soda- 

 salts. In coffee, which yields 3 '41 per cent, of ash, potash salts are most 

 abundant ; in all three substances the other salts which occur in the blood are also 

 present. 



Alcoholic drinks owe their action chiefly to the alcohol which they contain. 

 Alcohol, when taken into the body, undergoes certain changes and produces certain 

 effects : (1) About 95 per cent, of it is oxidised chiefly into C0 2 and H 2 0, so that 

 it is so far a source of heat. As it undergoes this change very readily, when taken 

 to a certain extent, it may act as a substitute for the consumption of the tissues of 

 the body, especially when the amount of food is insufficient. [Hammond found 

 that when he lived on an insufficient amount of food, alcohol, if given in a certain 

 quantity, supplied the place of the deficiency of food, and he even gained in weight. 

 If, however, sufficient food was taken, alcohol was unnecessary. As it interferes 

 with oxidation, and where there is a sufficient amount of other food, in health, it is 

 unnecessary for dietetic reasons.] Small doses diminish the decomposition of the 

 proteids to the extent of 6 to 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 thus 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. 



Z 



