U. SUZUKI. 



263 



contained very little proteids. The residue from the water 

 extract, was now treated with 1 % sodium chlorid solution. 

 This extract was also almost free from iron. The residue now 

 left, was treated with Q.2% caustic potash solution at the ordinary 

 temperature, frepuently stirred, and after standing for one day, 

 the clear supernatant solution was decanted, since it was difficult 

 to filter, and mixed with dilute acetic acid until a moderately 

 acid reaction was obtained. Hereby a greyish white flocculent 

 precipitate was abundantly produced. This precipitate, con- 

 sisting of several proteids, was washed with water, at first by 

 decantation, then collected on a filter, washed with water, 

 alcohol and ether, dried and pulverized. It contained : — 

 N^o.4% Fe = o.5% N : Fe = 100 : 4.9. 



Repeated tests have shown that nearly 60— 70% of the iron 

 contained in the seeds may thus be obtained in a form soluble 

 in dilute potash and separable from this solution with acetic 

 acid. 1 



(2) . In this test I applied the method of Stoklasa which 

 consists in extracting the seeds with a large quantity of 0.1% 

 hydrochloric acid, evaporating this extract at 30— 36°C and 

 subjecting the product thus obtained to artificial pepsin digestion. 

 The residue thus obtained was, however, so little (from 100 grams 

 of the seeds only 0.1— 0.2 gram was obtained) that further 

 examination was impossibble. 



(3) . 100 g. of the dry seeds were extracted with ether and 

 alcohol and the residue divided into two portions : — 



One portion (a) was boiled with water for half an hour 

 cooled to 6o c C and a small quantity of malt extract added to 

 saccharify the starch. The residue from filtration was washed 

 with water and then subjected to artificial pepsin digestion, 

 whereby a large part of the proteids was dissolved. The 

 remaining residue was now treated with dilute caustic potash 



1 Fearing that the extraction with potash might injure the original iron compounds to 

 some extent I used in another case dilute ammonia for extraction ; but I observed that 

 the iron compound is very imperfectly soluble in it. 



a) . Crude ferro-nuclein of Polygonum tinctorium was extracted with dilute ammo- 

 nia and precipitated with alcohol, subjected to artificial digestion the residue once more 

 dissolved in ammonia and precipitated with alcohol, it contained only N = 5-8%. 



b) . Crude ferro-nuclein of Indigofera tinctoria thus treated, yielded 



N = 6.6% Fe = o.5i%. 



