CHEMISTRY. 215 



extracts react strongly acid with litmus, and alkaline with lacmoid, a behavior 

 doubtless due to arid potassium phosphates together with organic acids or acid 

 salts. . . . 



"In consequence of the varying proportions of these substances in the different 

 kinds of seeds, different amounts of legumin are thus extracted from them. As the 

 proportion of phosphoric acid to potash in these leguminous seeds is much smaller 

 than m most of the other seeds which we have examined, the character of the salts 

 present may fairly be supposed to differ, and consequently the solubility of the pro- 

 teids would also differ when the seeds are extracted with water. . . . 



"Dissolved in dilute sodium chlorid solution, legumin is precipitated by a little 

 acetic acid, the precipitate being soluble in an excess of sodium chlorid. The solu- 

 bility of precipitates so produced depends on the relative proportions of salt and 

 acid. 



"Legumin extracted without neutralizing the natural acid of the seed and pre- 

 cipitated by dialysis, either directly or after precipitation with ammonium sulphate, 

 is usually converted to a large extent into insoluble 'albuminate.' This ' albuminate' 

 differs from the similar insoluble products obtained from most other globulins, for 

 when treated with salt solution it becomes gelatinous, can not be filtered, and on 

 washing with water shrinks, becomes opaque, and finally granular so that it can be 

 very readily washed on a filter. This substance appears to become hydrated by 

 salt solution and dehydrated by pure water. 



"If the acid of the seed is previously neutralized, the globulin extracted by salt 

 solution yields very little if any insoluble ' albuminate/ which indicates that the 

 latter is a product of the action of the acid of the seed. This fact is in harmony 

 with experiments described in a former paper of ours on the action of minute quan- 

 tities of acid on globulins. 1 In very dilute acids and alkalies in the absence of 

 salts, legumin dissolves readily and abundantly to solutions from which, if at once 

 neutralized, it is precipitated in a form soluble in sodium chlorid solution. By 

 this treatment no evidence of change has been detected. Solutions made with 

 hydrochloric acid are precipitated by a small excess of acid, but those made with 

 acetic acid are not precipitated by any excess of acid. 



" Solutions of legumin in 10 per cent sodium chlorid brine are not rendered turbid 

 by long heating in a boiling water bath. 



"Dissolved in 10 per cent sodium chlorid brine, legumin is precipitated by a very 

 little hydrochloric acid, but a relatively considerable amount of acetic acid is required 

 to produce a precipitate in such solutions. 



"Sodium chlorid solutions of legumin give large precipitates with tannic acid as 

 well as with picric acid, those formed by the latter dissolving in an excess of salt 

 solution if too much picric acid had not been previously added. With mercuric 

 chlorid no precipitate is produced. 



" With nitric acid, Millon's and Adamkiewics' tests, proteid reactions are obtained. 

 With the biuret test a violet color is given, which on standing becomes a deep rose 

 red, like that given by peptones. 



"Legumin has been supposed by some investigators to contain phosphorus, and 

 therefore to belong with the nucleo-proteids. A careful testing of thoroughly puri- 

 fied samples by fusing with caustic soda and nitrate, and treating the solution of 

 the fusion acidified with nitric acid, with ammonium molybdate, showed that in 

 some of the preparations only just detectable traces of phosphorus were present, 

 while other preparations contained none whatever. 



"Although we have examined large numbers of our preparations of the different 

 plant proteids for phosphorus, we have as yet found none which, in carefully puri- 

 fied samples, contained more than a few hundredths of a per cent of phosphorus; a 

 quantity so small that it is reasonable to consider it as a constituent of the ever- 

 present ash. 



1 Connecticut State Sta. Rpt. 1896, p. 369 (E. S. R., 9, p. 515). 



