ACTION OF VEGETABLES. 



57 



of a certain quantity of oxygen to the ele- 

 ments of theobromine, the characteristic 

 principle of the cacao bean, (theobroma 

 cacao,) yields the elements of taurine and 

 urea, of taurine, carbonic acid, and ammo- 

 nia, or of taurine and uric acid : 



1 at. theobromine C 18 N 6 H 10 O 4 1 

 22 at. water - HTO 22 ^ 



16 at. oxygen - O 16 j 



C 18 N 6 H 32 O 42 



4 at. taurine 

 1 at. urea 



C 2 N 2 H 4 O 2 



C 18 N 6 H 32 O 42 



or 



1 at. theobromine C 18 N 6 H 10 O 4 

 24 at. water - H^O 24 



16 at. oxygen O 16 



4 at. taurine 



2 at. carbonic acid 



2 at. ammonia 



C 16 N 4 H 28 O 40 



C 2 O 4 



N 2 H 6 



C 18 N 6 H 10 O 4 



O 14 



C 18 N 6 H 18 O 26 



C 8 N 2 H 14 O 20 

 C io N 4 H 4 O e 



1 at. theobromine 

 8 at. water 

 14 at. oxygen 



2 at. taurine 

 1 at. uric acid 



88. To see how the action of caffeine, as- 

 paragine, theobromine, &c. 5 may be ex- 

 plained, we must call to mind that the chief 

 constituent of the bile contains only 3*8 per 

 cent, of nitrogen, of which only the half, or 

 1-9 per cent., belongs to the taurine. 



Bile contains, in its natural state, water 

 and solid matter, in the proportion of 90 



Earts by weight of the former to 10 of the 

 itter. If we suppose these 10 parts by 

 weight of solid matter to be choleic acid, 

 with 3-87 per cent, of nitrogen, then 100 

 parts of fresh bile will contain 0-171 parts 

 of nitrogen in the shape of taurine. Now 

 this quantity is contained in 0'6 parts of 

 caffeine: or 2-^ths grains of caffeine can 

 give to an ounce of bile the nitrogen it con- 

 tains in the form of taurine. If an infusion 

 of tea contain no more than the ^th of a 

 grain of caffeine, still, if it contribute in 

 point of fact to the formation of bile, the 

 action, even of such a quantity, cannot be 

 looked upon as a nullity. Neither can it be 

 denied that in the case of an excess of non- 

 azotized food and a deficiency of motion, 

 which is required to cause the change of 

 matter in the tissues, and thus to yield the 

 nitrogenized product which enters into the 

 composition of the bile ; that in such a con- 

 dition, the health may be benefited by the 

 use of compounds which are capable of 

 supplying the place of the nitrogenized pro- 

 duct produced in the healthy state of the 

 body, and essential to the production of an 

 important element of respiration. In a che- 

 8 



mical sense and it is this alone which the 

 preceding remarks are intended to show 

 caffeine or theine, asparagine, and theobro- 

 mine are in virtue of their composition better 

 adapted to this purpose than all other nitro- 

 genized vegetable principles. The action of 

 these substances, in ordinary circumsla^-^s, 

 is not obvious, but it unquestionably exists. 



89. With respect to the action of the 

 other nitrogenized vegetable principles, such 

 as quinine, or the alkaloids of opium, &c., 

 which manifests itself, not in the processes 

 of secretion, but in phenomena of another 

 kind, physiologists and pathologists enter- 

 tain no doubt that it is exerted chiefly on 

 the brain and nerves. This action is com- 

 monly said to be dynamic that is, it acce- 

 lerates, or retards, or alters in some way the 

 phenomena of motion in animal life. If we 

 reflect that this action is exerted by sub- 

 stances which are material, tangible and 

 ponderable; that they disappear in the or- 

 ganism ; that a double dose acts more power- 

 fully than a single one; that, after a time, a 

 fresh dose must be given, if we wish to pro- 

 duce the action a second time ; all these 

 considerations, viewed chemically, permit 

 only one form of explanation ; the supposi- 

 tion, namely, that these compounds, by 

 means of their elements, take a share i-n the 

 formation of new, or the transformation of 

 existing brain and nervous matter. 



However strange the idea may, at first 

 sight, appear, that the alkaloids of opium or 

 of cinchona bark, the elements of codeine, 

 morphia, quinine, &c., may be converted 

 into constituents of brain and nervous mat- 

 ter, into organs of vital energy, from which 

 the organic motions of the body derive their 

 origin ; that these substances form a con- 

 stituent of that matter, by the removal of 

 which the seat of intellectual life, of sensa- 

 tion, and of consciousness, is annihilated ; 

 it is nevertheless certain, that all these 

 forms of power and activity are most closely 

 dependent, not only on the existence, but 

 also on a certain quality of the substance of 

 the brain, spinal marrow, and nerves; inso- 

 much that all the manifestations of the life 

 or vital energy of these modifications of 

 nervous matter, which are recognized as the 

 phenomena of motion, sensation, or feeling, 

 assume another form as soon as their com- 

 position is altered. The animal organism 

 has produced the brain and nerves out of 

 compounds furnished to it by vegetables ; 

 it is the constituents of the food of the 

 animal, which, in consequence of a series 

 of changes, have assumed the properties and 

 the structure which we find in the brain and 

 nerves. 



90. If it must be admitted as an unde- 

 niable truth, that the substance of the brain 

 and nerves is produced from the elements 

 of vegetable albumen, fibrine and caseine, 

 either alone, or with the aid of the elements 

 of non-azotized food or of the fat formed 

 from the latter, there is nothing absurd in 

 the opinion, that other constituent of vege 



