118 ANIMAL FUNCTIONS. 



Physiologists have contrived to extract the gastric 

 juice from the stomachs of various animals by means of 

 a sponge, which being introduced in the dry state is 

 withdrawn filled with the fluid, which being squeezed 

 out, the operation is repeated until a quantity for expe- 

 riment, is obtained. In a case described hereafter, this 

 was unnecessary, there being an orifice in the human 

 stomach, through which the juice was taken. The fluid 

 thus obtained is destitute of any sensible properties by 

 which its power as a solvent can be accounted for. It 

 is a clear transparent liquor, with little taste or smell. 

 But its action on various substances was found to be 

 very peculiar and striking. Spallanzani formerly the^ 

 most celebrated experimenter on this subject, found, that 

 when boiled meat was exposed to the action of this 

 agent, from the human stomach, that it lost its fibrous 

 texture, and was finally reduced to a pultaceous mass, 

 in imitation of the actual process of digestion. 



It was found also, that this juice from the stomachs of 

 animals of different races, produced different effects, 

 thus proving, what indeed had ever been proved by the 

 animals themselves, that the stomachs of eagles and 

 other carnivorous animals cannot digest vegetables, nor 

 can the sheep and ox digest meat. That from the stom- 

 ach of omnivorous man however, was found to dissolve 

 both vegetable and animal matter, with equal facility. 



Chemical effects of the Gastric Juice. Nearly all 

 physiologists of the present day, are agreed that the 

 change produced by the action of the gastric fluid, on 

 the aliment of the stomach, must be referred to chemi- 

 cal principles, and yet nothing can be detected in the 

 juice itself by chemical analysis, which in any degree 

 accounts for the phenomena produced. 



The coagulating effect of the gastric juice, is its most 

 obvious property. By this property, fluid substances, 

 whether animal or vegetable, which are capable of coagu- 

 lation, are rendered nearly solid. Thus, the white of 



When the gastric juice is extracted from the stomach and mixed with 

 food, what effect is produced? What was proved with respect to the 

 capacity of different animals to digest the same kind of food? On what 

 principle do physiologists account for the effects of the gastric juice? 



