178 A. B. MACALLUM. 
The dried and finely pulverised barley was put, with the acid 
alcohol, in a Soxhlet extraction apparatus and heat was applied 
for six hours, during which time the reagent was renewed once, 
but the second liquid extracted no iron. The result was the same 
when the strength of the acid in the solution was 2°5 per cent. 
From his experiments he concludes that nearly all the iron is 
combined with nuclein (a l’état de nucléine) and exclusively 
contained in the tegmen and embryo of the barley grain. Ina 
second publication! he describes the separation of an iron- 
holding nuclein from the malt-combs (touraillons) of barley, 
free from sulphur and in which the iron amounted to 0195 
per cent. The separation was made by extracting the pul- 
verised matter with a 1 per cent. solution of potash at 60°C. 
for some minutes, and filtering off under pressure the brown 
liquid, which was then neutralised with dilute hydrochloric 
acid. The precipitate formed was washed by decantation with 
water, then with alcohol and ether, and finally dried over 
sulphuric acid. 
Gilson ® found iron in the nucleinic elements, not only when 
ammonium sulphide, according to my method of using it, was 
employed, but also after treatment with other reagents and in 
nuclei which, without such treatment, gave no reaction for 
iron with the ordinary methods of demonstration. He specially 
mentions sulphuric acid and sulphurous anhydride as giving 
the best results, although others, among which he includes 
saline solutions, produce the same effects. He is, however, 
inclined to regard the iron demonstrated in the nuclein as due 
to a combination which is formed only after death, and similar 
to that which dead nuclein effects with many other substances, 
especially colouring matters. He showed that dead nuclein has 
a very strong aflinity for iron compounds, the nuclei of freshly 
extracted cells absorbing from a 0:05 per cent. solution of ferrous 
sulphate more iron than could be demonstrated in them when 
simply treated with sulphuric acid; and he maintains it is 
extremely difficult to ascertain whether nuclein in a living 
1 “Sur une nueléine végétale,” ‘Comptes Rendus,’ vol. exvi, p. 995, 1893, 
2 Loe, cit, 
