27 



cent. It appeared to consist entirely of lime and potash sulphate. 

 Phosphoric acid, magnesia, lithia, &c., were absent. Assuming 

 the lime sulphate and potash sulphate to be present in equal 

 equivalent proportions, which appeared to be the case, the above 

 amount of sulphate corresponds to about 0-66 per cent, of bases 

 which being deducted (in the case of No. 1., the ash analyzed) 

 leaves 21-26 per cent, of silica. The mixed sulphates when 

 heated were decidedly green in colour, but became white when 

 cold. I tried this over several times. 



X.-VEGETABLE RENNETS. 



The Kew Report for 1881 (pp. 36-37) contained some account 

 of WWiania coagulans, a well-known North-West Indian plant 

 which possesses the power of coagulating milk. The interest of 

 the subject arose from the fact that if cheese was to be made m 

 India the religious prejudices of the Hindoos would not allow the 

 rennet of the calf to be used for the purpose. 



The " Rennet Ferment " contained in the seeds was investigated 

 by Mr. Sheridan Lea. {Proc. Roy. Soc. Vol. XXXVI., pp. 5o-58.) 



Meanwhile Mr. W. R. Robertson, Agricultural Reporter to the 

 Government of Madras, in his Annual Report for 1882-3 (pp. 74, 

 75) gave an interesting account of some experiments on other 

 Indian plants with similar properties. 



As this is practically inaccessible it is reproduced here. 



"Attention having been directed to the properties of the berries 

 of WWia?ua coagulans for curdling milk in cheese-making, it 

 was thought desirable to try the properties of a nearly allied plant 

 Withania somni/era, a well-known plant in South India, where 

 Withania coagulans is unknown. 



"The curd on being sufBciently formed was broken up and the 

 whey separated as far^as this was possible ; the ^^^^^ J/^,^^ ^^ 

 a little salt had been added was put into a roughly made cheese 



"In one set of experiments twenty-one ollocks of milk were 

 taken and kept aside until the milk was famtly acid ^o test-paper 

 The milk was then gently heated to 110° F. ^^^^ dmded m^^^ 

 seven portions of three ollocks each. To the first were aaoea 

 twelve drops of churn milk, to the second twelve drops of lime- 

 juice, to the third twelve drops of tamarind-juice ^tj^\^^^' 

 sistency of the milk itself, to the fourth about a tf sP^oiif^l ^/ he 

 extract of the Withania berries, to the fifth twelve drops of th^ 

 juice of the bilimbi fruit (Averrhoa Bdtmbi), to the ^^^^^^ ^^ 

 juice of twelve Withania berries, and to the ^evemn aooui 

 drop of the milky juice of Epicarpurus orient f^i^rzy^ra 

 or Cootty pela). All these agents were tested with b^ne litmus 

 .r, aL^Jy .had a. distinctly, acid reachon^^ I-^thrf^^^^^ 



found to have changed i 



with a layer of clear supernatant whey. 



that this is quite equal to rennet ; it d 



