118 



muslin bag; this bag and contents were placed under a faucet of run- 

 ning water and allowed to remain for five hours. Upon opening the 

 bag it was found thut only a few shreds of meat remained. 



In order to demonstrate that the action was not that of a washing 

 away process due to force of the water, a check experiment was made 

 without the ferment, here the loss in weight only amounted to about 

 fifty per cent. 



This experiment seems to show that the enzyme combined with 

 and hydrated the fibres of the meat. The products of this combi- 

 nation are soluble, and are removed by the action of water or other 

 fluids ; furthermore, in the process of washing away the soluble 

 products, the ferment is left behind to act upon a fresh portion of the 

 fibre, in turn giving rise to soluble products or peptones. 



This experiment was made in order to imitate certain known condi- 

 tions present in the process of digestion, where there is a constant 

 stream of fluid in the iutestmal tract. Taken with other experiments 

 this result seems to show that ferments of the papaw act very energe- 

 tically in a small amount of fluid, and will also act in a stream of water. 



The influence of reaction upon the ferments of the papaw form an 

 interesting comparison with those of the animal ferments. 



The power of pepsin is destroyed in alkaline solution, such as lime 

 water, sodium bicarbonate, ammonia, etc. ; on the other hand the 

 activity of pancreatin, ptyalin or distaste is inhibited in acid solution. 

 The papaw enzyme is active in acid, neutral or alkaline solution ; but 

 pepsin and pancreatin cannot be mixed together in solution either 

 acid, alkaline or neutral, and still preserve their characteristics ; whereas, 

 the ferments of the papaw can be mixed with other ferments in a so- 

 lution of any reaction. Pepsin is inert in a neutral solution, and is 

 destroyed in solutions containing traces of alkalinity. If an alkaline 

 solution of pepsin be made acid, the pepsin action is not restored ; pan- 

 creatin acts slowly in neutral solutions, and is destroyed in acid solu- 

 tion. If an acid solution of pancreatin be made alkaline, the pancreatin 

 action will not be restored. The papaw ferments are active in neutral 

 solutions ; their activity is enhanced when such solution is made acid, 

 and if such acid solution be in turn made alkaline, the ferment will 

 still remain active. In fact, the changing of solution of the papaw 

 ferments from acid to neutral, then to alkaline ; then reversing the 

 order to neutral, acid and alkaline, or in fact, changing the order of 

 reaction almost indefinitely, does not thereby destroy the ferment 

 which seems to remain active under all reactions and conditions. 



Certain physical changes in the proteid substances acted upon are 

 characteristic of these enzymes of the papaw. For instance : when 

 raw blood fibrin or raw beef is acted upon with an alkaline solution of 

 these ferments, there is an immediate softening to a jelly-like mass in 

 which the fibres lose their individuality, this jelly gradually becoming 

 thinner under the further action of the ferment.^ ^ 



In the case of cooked beef in either alkaline or acid solution, the ac- 



^° This action in the casp of blood fibrin is quite striking, and advantage is 

 taken of this property in theraputics where a solution of the ferments is used as a 

 solvent for the false membrane of diphtheria, a substanao quite analogous to blood 

 fibrin. 



