124 THE MEDICINAL PLANTS OF THE PHILIPPINES 



Soft resin 0.110 



Brown resin 2.776 



Albuminoids 0.006 



Papayotin (Papain of Wurtz) 1.059 



Extractive matter 5.303 



Malic acid 0.443 



Peptic material and salts 7.100 



Water 74.971 



The milky juice is neutral and coagulates rapidly, separating 

 in two parts : a kind of insoluble pulp and a limpid colorless 

 serum. If combined with fibrin, raw meat, white of egg or 

 gluten it gradually softens them and completely dissolves them 

 in 3 or 4 hours in vitro at 40 C. Combined with milk it 

 coagulates it and soon precipitates the casein which is also dis- 

 solved a little later. It digests lumbricoids and tape-worms 

 and the false membrane of croup, in a few hours. According 

 to Wurtz and Bouchut papain is prepared as follows : 



The fluid juice or the aqueous solution of the milky exudate 

 is precipitated by the addition of ten times the volume of 

 alcohol. The precipitate, after treating again with concen- 

 trated alcohol, is dissolved in water and the addition of sub- 

 acetate of lead eliminates the albuminoids and peptones but 

 does not precipitate the papain. The liquid is filtered and the 

 lead salts separated by means of a current of hydrogen sulphide. 

 It is filtered again and alcohol added gradually, which process 

 first precipitates whatever sulphate of lead may have passed 

 through the filter, and then the papain. 



Papain is an amorphous substance, perfectly white, soluble 

 in water, insipid, odorless. An aqueous solution, if shaken 

 violently, foams like a solution of soap. Boiling makes it 

 turbid and when concentrated it has a slightly astringent taste. 

 It is precipitated by hydrochloric, nitric, picric and the meta- 

 phosphoric acids. Trommer's test gives it a beautiful blue 

 violet color which, on boiling, changes to a red violet. 



