388 



Profs. A. Gamgee and W. Jones. 



[Feb. 9, 



ing it in any degree pure, attempts at purification being attended 

 with such loss that the yield was too small. 



Hammarsten remarked that among the impurities most difficult to- 

 separate was the blood-colouring matter, as well as another colouring 

 matter which he believed to be produced by the action of the air on 

 the nucleoproteid itself. Further, another impurity adhering to the 

 nucleoproteid was found by Hammarsten to be trypsin, which he was. 

 unable to separate from it. He remarks, indeed, that the proteolytic 

 activity of the substance is so intense that in no other way could he 

 obtain so powerfully acting a trypsin. 



Having, for the reasons above stated, abandoned the study of the 

 interesting mother-substance, his nucleoproteid-a, Hammarsten then 

 directed his attention to the /3-body. This body, he did not seek to 

 obtain by the decomposition of the mother substance, of which it is a 

 product, but by adopting the following method : — he boiled the finely 

 comminuted and perfectly fresh pancreatic gland of the ox in water 

 and obtained, after nitration, a perfectly clear, faintly yellow solution,, 

 to which he added, after cooling, from 1 to 2 parts of hydrochloric 

 acid, or from 5 to 10 parts of acetic acid per 1000 parts of the liquid. 

 In this manner he obtained an abundant, white, flocculent precipitate. 

 He dissolved the substance thus precipitated in water, with the aid of 

 the least possible quantity of alkali and reprecipitated it by adding 

 an excess of acid. By repeating this process several times, the body 

 originally precipitated was purified, so far as such a method can effect 

 the purpose. 



It must be clearly insisted upon that, as Hammarsten himself 

 pointed out, the so-called nucleoproteid-/? does not represent an 

 original proximate principle of the pancreas, but is a nuclein pro- 

 duced from the original mother nucleoproteid (or nucleoproteids by 

 the action of boiling water. It is certainly in no spirit of detraction 

 or want of respect for the eminent Swedish chemist, that we add the 

 remark that the study of a nuclein to be satisfactory should, if 

 possible, take as its starting point the pure mother substance, of which 

 it is a product of decomposition, rather than the animal tissue which 

 contains that substance. In the case of Hammarsten's nucleoproteid-/?,. 

 one can at present only assert that it is a nuclein or a mixture of 

 nucleins produced by the action of boiling water on the nucleoproteids, 

 properly so called, existing preformed in the tissue of the pancreas. 



These strictures notwithstanding, we have to point out the remark 

 ablj T interesting facts which were discovered by Hammarsten in the 

 course of the investigation under review. He made a series of ulti- 

 mate organic analyses of different specimens of this nuclein, and 

 showed that whilst its solutions when boiled with Fehling's solution 

 gave no trace of reduction, the body when heated on the water-bath 

 with dilute sulphuric acid, furnished a highly reducing substance. 



