116 



acidulated with hydrochloric acid (5-100) ; evaporate the extract, 

 wash with water acidulated with hydrochloric acid (2-100). This 

 solution is then washed with ether ; made alkaline with sodium hydrate 

 and the alkaloid washed out in chloroform or ether. In my experi- 

 ments the yield was small. I have noted indications of alkaloidal 

 reaction with Mayer's reagent in the alkaline ether washings, from the 

 latex, but it cannot be stated that the alkaloid is present in this product. 



The alkaloid, carpaine, is soluble in absolute alcohol, amylic alcohol, 

 chloroform, benzine and in water acidulated with hydrochloric acid. 



A solution of carpaine reacts with indicators as follows : — red litmus 

 paper is turned blue; haematoxylin, deep rose or wine ; rosolic acid, 

 deep rose ; cochineal deep rose ; methyl-orange, yellow ; lacmoid, no 

 change. Phenolphtalein causes a turbidity with the usual red, but the 

 reaction is obscure in the presence of alcohol. 



The physiological action of this alkaloid is quite similar to that of 

 digitalis, a heart depressant. 



MARKET PREPARATIONS OF THE PAPAW, 



There are numerous preparations in our own and in the European 

 markets claiming to be the ferment of the papaw. These are sold 

 under the name of * papain," "papayotin," "caroid," "papoid," etc. 



From a somewhat extended examination I am quite satisfied that 

 several of the preparations named are the dried and powdered papaw 

 milk. In this case they bear the same relation to the true separated 

 ferment as the dried mucous membrane of the stomach might bear to 

 purified pepsin. Some of these so called papains _ retain the waxy, 

 rubber-like constituents and the acrid, irritating resins of the milk. 



The application to such crude material of the term " papain," or 

 any similar name which would imply the isolated ferment, is mislead- 

 ing and should be abandoned. The dried juice of the papaw, or a mix- 

 ture of the dried juice with any other ferments, should be properly 

 labelled. From these crude preparations, the true ferment can be sepa- 

 rated by extraction with water and precipitation with alcohol. In a 

 few experiments which I have tried, some of the crude preparations 

 were found to contain about twenty per cent, of the ferment-bearing 



bodies (albuminous). , • <. -u 



There are, however, preparations in the market which consist of the 

 more or less purified and separated ferment, or, more accurately speak- 

 ing, consisting of the separated proteids ; with which the ferments 

 are associated. 



I know of no standard by which these marked preparations can be 

 judged. They vary greatly in their proteolytic action. In such as 

 may be prepared by simple drying of the milk, no two lots can be 

 alike. These will be found to vary in colour, to emit an offensive odour 

 and to have a marked acrid disagreeable taste, producing in several in- 

 stances in my experience, quite a sharp caustic action. 



The dried papaw juice is usually the more energetic in the begin- 

 ning of digestive action than is the purified ferment, but this energetic 

 action of the dried juice apparently soon ceases, while the pure ferment, 

 though slower in immediate action, continues its activity for many 

 hours. Upon treating the preparations made of the dried juice with 

 ether, chloroform, benzine or alcohol, evaporating the solvent, the 

 waxy resinous and rubber-like residue elsewhere spoken of will remain. 



