RENNET. 101 



an ash tub for the amount prepared weekly. To keep the 

 wood from tainting, we invariably, every time \ve dipped 

 out rennet and exposed new surface, rubbed it with salt. 



EXCLUDING AIR. 



Rennet could be much more easily kept sweet if put 

 in an air-tight vessel. The "American Dispensatory" 

 says: " When gastric juice is completely protected from 

 the ail 1 it may be kept unchanged for a longtime; but on 

 exposure it speedily undergoes decomposition, acquires 

 a very offensive odor, and loses its characteristic diges- 

 tive property." We think that the Dispensatory is 

 right. The composition of pure gastric juice is as fol- 

 lows: W T ater,97.00; salts, 1.75; pepsin, 1.25; total, 100.00. 

 There is also a small amount of free acid. Both rennet 

 extract and pepsin are used as medicine. 



