X. A, 1 Pratt: Papain 3 



tion of the general procedure from tapping the fruit to export 

 of the gum should be of interest. 



Kegalle is situated between Colombo and the Royal Botanic 

 Gardens at Paradeniya, with an annual rainfall of from 190 

 to 250 centimeters and with soil conditions well adapted to the 

 growth of papayas. Gathering and drying the latex is entirely 

 in the hands of ignorant natives, who are not capable of appre- 

 ciating the care and cleanliness which should always be employed 

 in dealing with a sensitive material, such as an enzyme. Good 

 results cannot be expected, and it is rather surprising that the 

 final product shows any proteolytic activity, especially as gross 

 adulteration is the rule rather than the exception. The papaya 

 trees are not planted with any degree of regularity, but are 

 found scattered through coconut and areca-palm groves. They 

 receive neither cultivation nor care, but in spite of difficulties 

 continue to bear fruit and support a rather numerous population. 



Preparations for gathering latex are very simple, and consist 

 in cutting and forming the leaf sheath of an areca-palm leaf into 

 a shallow basket. A crossbar is tied to the papaya tree at a 

 convenient height, and the basket is hung beneath the unripe 

 fruit, in which slight cuts are made longitudinally, whereupon 

 the milky juice exudes and drops into the basket. The flow is 

 rapid for a few seconds, but becomes slower and slower as the 

 latex coagulates, until it ceases entirely. The jellylike frag- 

 ments adhering to the fruit are scraped off with a paddle cut 

 from a leafstalk and added to the contents of the basket which 

 are stirred for a few minutes until coagulation takes place (Plate 

 I). It is a common practice to add boiled rice starch at this 

 point for the purpose of increasing the weight and lightening 

 the final color of the gum, the amount of adulterant varying 

 from about 10 to as much as 80 per cent. Other extraneous 

 material, such as clay, bread crumbs, dried fruit, and India rub- 

 ber latex, are occasionally used. 



The juice is now spread out on papers in the sun to dry, 

 three or four days generally being sufficient for the purpose. 

 On several occasions, I noticed papers of partially dried gum 

 exposed to clouds of dust and dirt from near-by thoroughfares. 

 The color gradually darkens as the drying proceeds, until the 

 final product is dark brown to nearly black in the case of straight 

 gum or light brown where large percentages of starch have 

 been added. The former is known to Colombo brokers as No. 1 

 and the latter as No. 2. Foreign markets demand a light-colored 

 papain, and will not accept No. 1 grade. Pure gum, light in 



