106 POWER OF ANIMAL MEMBRANE. 



the air, or dried, and then placed in contact with such 

 substances, the sugar is changed, according to the state 

 of decomposition of the animal matter, either into lactic 

 acid, into mannite and mucilage, or into alcohol and 

 carbonic acid ; while milk is instantly coagulated. An 

 ordinary animal bladder retains, when dry, all its prop- 

 erties unchanged ; but when exposed to air and moist- 

 ure, it undergoes a change not indicated by any obvious 

 external signs. If, in this state, it be placed in a solu- 

 tion of sugar of milk, that substance is quickly changed 

 into lactic acid. 



10. The fresh lining membrane of the stomach of 

 a calf, digested with weak muriatic acid, gives to this 

 fluid no power of dissolving boiled flesh or coagulated 

 white of egg. But if previously allowed to dry, or if 

 left for a time in water, it then yields, to water acidulated 

 with muriatic acid, a substance in minute quantity, the 

 decomposition of which is already commenced, and is 

 completed in the solution. If coagulated albumen be 

 placed in this solution, the state of decomposition is 

 communicated to it, first at the edges, which become 

 translucent, pass into a mucilage, and finally dissolve. 

 The same change gradually affects the whole mass, and 

 at last it is entirely dissolved, with the exception of fatty 

 particles, which render the solution turbid. Oxygen is 

 conveyed to every part of the body by the arterial 

 blood ; moisture is everywhere present ; and thus we 

 have united the chief conditions of all transformations 

 in the animal body. 



Thus, as in the germination of seeds, the presence 



