192 A. B. MACALLUM. 
the other acid alcohols, to the parts in which treatment 
with the glycerine and sulphide mixture demonstrates its 
occurrence. 
In describing the properties of hydrochloric acid alcohol, 
Bunge expressly states that while it extracts inorganic iron 
it does not remove the iron from the nuclein (hzmatogen) of 
egg-yolk.! Thisis not quite correct, for when hard-boiled yolk 
is treated with ammonium sulphide it gives only a feeble reac- 
tion for iron, even when kept for twenty-four hours at an 
elevated temperature ; but when it has been acted on by a 
quantity of Bunge’s fluid for a day at 30—35° C., the applica- 
tion of ammonium sulphide, after all traces of the acid have 
been removed with alcohol, gives an immediate and marked 
reaction for iron. The iron under such conditions must be 
in the form of chloride, and as an inorganic compound it 
should be extracted by the reagent, if Bunge’s views con- 
cerning the properties of the latter be correct, but this 
happens only when the quantity of the yolk so treated is 
very small, and then the whole of the iron is removed in a few 
days, this fact demonstrating clearly that the reagent in its 
action makes no distinction between inorganic and organic 
iron. The latter is in its liberation from the ‘‘ masked ”’ con- 
dition converted into the inorganic form, and it depends on the 
quantity of yolk used whether or not the extraction may keep 
pace with this conversion. If the quantity is large, the libera- 
tion of the iron from its organic combination entails a diminu- 
tion of the acidity of the reagent, and at length the extraction 
of the liberated iron ceases. It commences again only when a 
fresh quantity of the reagent is substituted for the exhausted 
fluid. 
The results of its action upon the iron-containing nucleo- 
albumin of yolk are therefore practically similar to those which 
it gives when applied to animal and vegetable tissues. 
The fact that a considerable diminution of the acidity of 
hydrochloric acid alcohol allows the liberated iron to be retained 
1 «Ueber die Assimilation des Hisens,” ‘Zeit fiir Physiol. Chemie,’ vol. 
ix, 1885, p. 49. 
