Hints on the Sulject of Animal Secretions, I09 



the idea that the animal secretions may be produced by the 

 same means. ' 



To prosecute this inquiry with every advantage, requires 

 a knowledge of an.iiomy, physiology, and chemistry, rarely 

 to be met with in the same person. [ have the 2 lb re availed 

 myself of the assistance of the different members of this 

 society, the object of which is the improvement of animal 

 chemistry. Their intimate acqiiaint:^ncc with ihesebranchcs 

 of science renders them peculiarly fiued for such an un- 

 ilertaking. 



It is one of the most important subjects to v;hich Mr. 

 Davy's discoveries can be applied, and he has given it the 

 consideration it deserves. 



The Voltaic haltery is met with in the torpedo and elec- 

 trical eel; and although it is given only as a means of 

 catching their prey, and defending themselves, and there- 

 foVe not imnn-^diately applicable to the present inquiry, yet 

 it furnishes two important facts: one, that a Voltaic battery 

 can be formed in a living animal ; the other, that nerves are 

 essentially necessary for its management; for, in these fish, 

 the nerves connected with the electrical organs exceed 

 those that go to all the other |)aris of the tish in the pro- 

 portion of twenty to one. The nerves are made up of an 

 infinite number of small fibres, a structure so different from 

 that of the electric organ, that they are evidently not fitted 

 to form a Voltaic battery of high -power; but their struc- 

 ture appears to Mr. Davy to adapt them to receive and pre- 

 serve a small electrical power. 



That the nerves arranged with- muscles, so as to form a 

 Voltaic battery, have a power of accumulating and com- 



tures ; at that time Dr. Young's Syllabus was not published, and Dr. Wol- 

 laston's opinions were unknown to me. 



Dr. Berzelius, professor of chemistry at Stockholm, published a work on 

 Animal Cliemistry, in the year 1806, in the Swedish language, in which he 

 states, in several places, that he believes the secretions in animals to depend 

 upon the nerves,, although he is unable to explain how the effect is produced. 

 In proof of his opinion, t'le following experiment is adduced : 



" Trace all the nerves leading to any secretory organ in a living animal, 

 and divide them, b«;ing careful to injure the blood vessels and the structure 

 of the organ itself, as little as may be ; notwithstand":ig the continued circu- 

 lation of the blood, the organ will as little secrete its usual fluid, as an eye 

 deprived of its nerve can see, or a muscle whose perve has been divided cai\ 

 move. We may therefore easily conceive, that any trifling alteration in the 

 nerves of a gland may materially affect its secretion, the supply of blood 

 being in every way perfect." 



He says, the agency of the nerves in secretion has generally been disre- 

 garded, because our attention is only called U) their secret mode of acting^ 

 when we discover the insufficiency of all other explanation. Dr. BerzeUus*% 

 Tiyorjc was shown to jne by Mt. Pavy while ihis paper was in the press. 



municating 



