628 SCIENCE PROGRESS 



in solution. It thus may be employed in cases in which a direct 

 determination would present difficulty. 



A type of work which appears capable of extending very 

 considerably our knowledge of the mechanism of the reactivity 

 of a solvent, when participating stoicheiometrically in a reaction, 

 has been commenced b}' Holmes and Jones {Journ. Amer. 

 Chem. Soc. 38, 105, 1916) under the title " The Action of Salts 

 with water of hydration and without water of hydration on 

 the velocity of saponification of esters." The object is to find 

 out, if possible, whether there is any difference between the 

 reactivity of " free " water, i.e. solvent, and water present 

 in a" bound " form as water of hydration in certain dissolved 

 salts. The mode of testing the relative reactivity is by measur- 

 ing the rate of saponification of methyl acetate and methyl 

 formate. It is found that in general the velocity of saponifi- 

 cation is greater in the case of highly hydrated salts than with 

 those in which hydration is absent and the reactivity is there- 

 fore due to the solvent. The conclusion is that bound water 

 is more reactive than free water. This is a very striking 

 result. Naturally one has to be certain that the two series of 

 measurements are truly comparable. The authors state that 

 the acidity produced by the hydrolysis of the salts will not 

 account for the difference in the speed. One would wish this 

 were more clearly demonstrated. In any event the further 

 investigations promised on these lines will be awaited with 

 interest. 



As a problem of considerable technical importance, the 

 catalytic bleaching of palm oil has been investigated by Sastry 

 {Trans. Chem. Soc. 107, 1828, 1915). The object is to oxidise 

 the material as rapidly as possible, without its being otherwise 

 attacked, and to avoid the labour and expenditure of time 

 required if the oxidising agent has to be washed out of the 

 oil. The author's experiments consist in blowing air or oxygen 

 through the oil in the presence of various catalysts, both oil 

 and air being kept at a temperature of 80-90 C. Among the 

 catalysts employed were salts of manganese, lead, cobalt, iron, 

 and nickel. The best catalysts were found to be the salts of 

 cobalt and manganese, especially the borates of these metals. 

 The larger the amount of catalyst present the shorter the time 

 required. The bleaching effect is permanent, no colour having 

 manifested itself after keeping for fifteen months. The 



