66 MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



The amount of this coagiihible proteid, wliich has the properties characteristic of an alhuinin, 

 was too small for analysis (0.5 gram from 2^ kilograms of oats), but its importance in a study of 

 these bodies is great, for Weyl has undertaken to classify the vegetable proteids after the manner 

 now commonly adopted for those of animal origin, aud has stated that the extracts of oats and 

 other seeds in JO per cent sodium chloride solution coagulate at 55° to 60° C, and consequently 

 contain a myosin, since the myosin from animal muscle (coagulates under these conditions at this- 

 temperature. He also states that besides myosin, viteUin exists in these seeds, as shown by filter- 

 ing out the coagulum formed at 00° C. and heating the solution gradually to 75°, when a second 

 coagulation takes place. 



The proteid soluble in salt solutions, to be described further on, was found, when dissolved in 

 a 10 per cent sodium chloride solution, to become turbid at 81° C. and to form flocks at 97°. This, 

 then, has a coagulation point not far from that of vitellin, but it differs fi-om that substance in 

 being readily precipitated by sodium chloride even before saturation. 



It is seen from the experiments above described that the presence of a very little coagulable 

 substance may be highly misleading, and gives no certain basis for classifying or identifying the 

 vegetable proteids, unless each body is separated from all the others and examined in detail by 

 itself. Weyl did not attempt this, except for one i>reparation from the Brazil nut {Bertholletia), 

 and therefore his conclusions based on coagulation points need further study before they can be 

 accepted. 



Precipitate. — The precipitate from the dialyzer, filtered out of the solution just considered, 

 was treated with 10 per cent sodium chloride solution. A part of the substance which did not 

 dissolve was filtered out, and the clear filtrate dialyzed till free from chlorides, when the proteid 

 was found to be precipitated. This precipitate was filtered out, washed with water, absolute alco- 

 hol and ether, and dried over sulphuric acid. 



The (jlohulin thus obtained, " 13," had the following properties: 



Iti 10 i>er cent brine of sodium chloride it dissolved readily to a clear solution. Addition of an 

 equal volume of water to this solution produced a copious precipitate. Addition of sodium 

 chloride gave a large precipitate even before saturation. When the solution was diluted till 

 turbid, the turbidity disappeared on warming gently. 



Very dilute acetic or hydrochloric acid" dissolved the substance readily when salts were not 

 present. The addition of more acid gave no precipitate. Addition of a very little sodiixui chloride 

 to a solution of the substance in very dilute acid made a slight precipitate; the addition of more 

 sodium chloride threw down an abundant curdy precipitate. The more acid present, the more 

 salt solution was required to produce a precipitate, and the more salt solution present, the less the 

 amount of acid required for precipitation. 



Dilute solution of citric acid in water (1 : 2000) gave results like acetic acid and dissolved the 

 substance readily to a solution which was not coagulated on boiling. 



From solution of the substance in 10 per cent brine, hydrochloric acid throws down a piecipi- 



, tate which is wholly insoluble even in strong solution of sodium carbonate (the filtrate giving no 



reaction with sulphate of* copper and caustic potash), and is also insoluble in an excess of dilute 



acid. Acetic acid, on the other hand, gives a precipitate which, at first, is readily soluble in very 



dilute sodium carbonate, but the solution, on standing, becomes turbid. 



Hydrochloric acid, in the presence of salt, converts this proteid into a "coagulated proteid;" 

 acetic and citric acids transform it into an " albuminate." 



The preparation gave the usual reactions with Millon's reagent, with cupric sulphate and 

 potash, and with nitric acid. The solution in 10 per ceut brine of sodium chloride on heating 

 became turbid at 81° C, aud at 07° C. the formation of flocks occurred. The same solution 

 allowed to stand at summer temperature for more than a month showed no signs of turbidity, 

 decomposition being prevented by adding from time to time a drop of a 20 per cent alcoholic solu- 

 tion of thymol. The composition of this globulin is here given: 



