378 Prof. H. E. Armstrong and Dr. E. Ormerod. [June 14, 



of which 0'3 gramme of seed residue, 5 - grammes of castor oil and 5 c.c. 

 acid of the concentration stated at the head of the table were digested 

 together during 20 hours. 



Concentration of acid... 



N/100. 



N/50. 



N/17. 



N/10. 



3N/10. 



N/2. 





5 "45 



14 -9 



15 -4 



14 -6 



14 -6 



13-6 



Succinic 



2-8 



14 -6 



15 -5 



15 -4 



14-3 



12-2 





7 -25 



15 -3 



15 -2 



14 -7 



7-3 



1 -1 





6-95 



15 -4 



14 -5 



14 -2 



2 -0 





That the strength of the acid is a factor in the action can scarcely be 

 doubted when the above values are contrasted with the values deduced from 

 the electrical conductivity given by Kohlrausch : — 



Acetic acid K = 0-0018 



Succinic „ - 006 



Citric „ 0-082 



Tartaric . „ 0-097 



It is easy to understand that the acids produced when natural fats and oils 

 are hydrolysed have little or no influence on the enzyme, as they are not only 

 weak acids, but also very slightly soluble in water ; the influence of the acid 

 therefore is soon at a maximum. 



Dr. Nicloux, in drawing attention to his work on Pticinus Lipase,* has 

 stated that the cytoplasm separated from castor oil seed " acts on fat in the 

 same way as an enzyme and follows all the laws of enzyme action " ; yet he 

 concludes, that, " Nevertheless the active substance of which cytoplasm is 

 but probably the support is not an enzyme ; this substance " — which he 

 proposes to call lipaseidine — " is destroyed by water as soon as it is no longer 

 protected by fats." 



We cannot help thinking that this conclusion is illogical and that the 

 destruction of the lipase prepared by Nicloux is probably to be traced to an 

 admixed proteoclastic enzyme rather than to water. The substance in 

 question was obtained by expressing the oil from the seed, then centri- 

 fugalising the oil to separate the suspended solid matter and washing this latter 

 free from oil with carbon bisulphide. It was intensely active as a lipoclast. 



The material we have used, though free from oil, is but slightly affected by 

 water or dilute acids. After such treatment, however, it loses to a con- 

 siderable extent the property of causing oil to form an emulsion with water ; 



* Ibid., B, 1906, vol. 77, p. 454. 



