332 



Dr. S. Martin. On the 



[May 5, 



making a watery extract of the crushed seeds and precipitating with 

 alcohol, the precipitate being afterwards collected and dried. 



Before proceeding to an examination of the physiological action of 

 the jequirity, it seemed to me desirable to determine the kind of 

 proteids present in the seeds, and the present commuuica/tion em- 

 bodies the results of the inquiries made with a view to such deter- 

 mination. 



Method of Extraction of the Proteids. 



The method used was based on the supposition that the proteids 

 present in Abrus were similar to those in other seeds, consisting 

 chiefly of proteids of the globulin and albumose classes. 



The finely ground seeds were shaken first of all with chloroform to 

 remove the red cuticle which sinks in this liquid, so that the yellow 

 kernel-powder could be readily removed, and obtained in the dry state 

 by allowing the chloroform to evaporate. 



The powder obtained was then extracted with 15 per cent, sodium 

 chloride solution for twenty-four hours, and the mixture filtered. The 

 yellowish filtrate was distinctly acid and gave a copious precipitate on 

 boiling. The proteids were separated from this filtrate in two 

 ways : — 



(1.) Saturation with neutral ammonium sulphate and shaking for 

 four hours throws down all the proteids in solution ; the filtrate, after 

 saturation, giving none of the proteid tests. 



(2.) Saturation with sodium chloride and shaking for many hours 

 gives only a scanty precipitate, which becomes copious on adding a 

 large excess of glacial acetic acid. All the proteids are only with 

 difficulty precipitated by this mode of saturation, even after prolonged 

 shaking. 



Since ammonium sulphate so readily throws down all the proteids 

 in solution, the precipitate caused by it was used in the following 

 manner in the examination of the proteids : — The precipitate was 

 collected and dissolved by adding distilled water, and the solution 

 dialysed in running water (with thymol) for five to seven days. 



Dialysis caused a copious precipitate, which was collected and 

 washed with distilled water (previously boiled to remove carbon 

 dioxide) until no proteid in solution was present in the washings. 

 The precipitate was then dried over sulphuric acid. The residue was 

 in dark-brown scales. It consisted of globulin with some colouring 

 matter. 



It is not possible to remove all the globulin by dialysis, so the 

 liquid, after dialysing for seven days, was filtered into rectified spirit, 

 which precipitated the remaining proteids. After standing under the 

 alcohol six to eight weeks the globulin was coagulated, and the preci- 

 pitate was collected, dried, and treated with distilled water, which 



