198 A. B. MACALLUM. 
iron, while Emich, at the request of Molisch,' examined a 
quantity of pure chlorophyll and found it free from iron. 
Molisch also made observations on the subject, and determined 
that, after every care was taken to prevent contamination with 
iron salts through impure extracting fluids, the ash of chlorophyll 
gave not the slightest reaction for the meta]. Gautier’ also 
claims that it does not contain iron. Schunk,® on the other 
hand, found ferric oxide in the ash of phylloxanthin, one of 
the decomposition products of chlorophyll, even after that com- 
pound had been treated with acids and after repeated solution 
of it in ether. 
The material from chlorophyll-holding organisms was, in all 
cases, thoroughly freed from that substance before the disposi- 
tion of the iron in it was examined. Chorophyll, however, has 
not in any of my preparations yielded any evidence that it 
contains iron, nor does its presence or absence at all affect the 
question of the occurrence of iron in other compounds in the 
cell. This is very distinctly shown when one compares the 
results, obtained from experiments on vegetable cells holding 
chlorophyll, with those determining the distribution of iron in 
Fungi and in Monotropa uniflora and Corallorhiza mul- 
tiflora, which are destitute of chlorophyll. In the two latter 
the disposition of the assimilated iron is as it is in the chloro- 
phyll-holding Phanerogamous plants, and consequently one 
may dismiss the objection that the pigment constitutes the 
source of the iron demonstrated by my methods in the nuclei 
of vegetable cells. It may be proved also from Monotropa* 
1 Op. cit., p. 87. 
2 ‘Chemie Biologique,’ Paris, 1892, p. 20. 
3 “Contributions to the Chemistry of Chlorophyll,” No. 4, ‘Proceedings 
Roy. Soe.,’ vol. 1, 1891, p. 302. 
4 The importance of Monotropa material for control purposes renders a 
short description of the methods of preparation employed upon it necessary. 
This plant, when hardened in alcohol, blackens more or less through the pro- 
duction on the part of the dying cells of a dark greenish-blue pigment, but 
it remains colourless when fixed in solutions of corrosive sublimate, a reagent 
whose use is, for reasons already mentioned, objectionable when ammonium 
sulphide is to be employed. To obtain material on which this reagent may be 
