ON THE MICRO-CHEMISTRY OF CELLS. 609 
The Micro-chemistry of Cells——Interim Report of the Committee, con- 
sisting of Professor EH. A. SCHAFER (Chairman), Professor E. 
Ray LaAnNKESTER, Professor W. D. Haturpurton, Mr. G. C. 
Bourne, and Professor A. B. Macau (Secretary). 
THE Committee beg to present an interim report. 
The investigation was directed along the following lines : 
(1) The detection and localisation of iodine in animal cells and organs. 
In regard to the detection of this element considerable difficulty was 
experienced in finding a suitable reaction ; for starch, the usual test for 
iodine, being a colloid when in solution, cannot penetrate iodine-holding 
colloid tissue-material. Another difficulty consisted in the firmness with 
which organic compounds of iodine hold the element in ‘masked’ com- 
bination. Both dithiculties were overcome by the discovery that solutions 
of hydrochloric acid and mercuric chloride, under certain conditions, not 
only set the iodine free in an inorganic form but yield it also as red mercuric 
iodide. By this method it has been found that the iodine compound of 
the thyroid gland is confined to its colloid masses, the gland cells being 
free from traces even of the element. The ‘colloid’ masses of the pitui- 
tary body gave no evidence of the presence of iodine, nor was any trace of 
it found in the other organs. Experiments in this line are being made on 
the tissues of certain invertebrates. 
(2) The micro-chemical localisation of sulphur of inorganic and organic 
combinations in animal cells. The reaction employed is that obtained 
when a mixture of solutions of lead acetate and potassic hydrate with 
glycerine, in such proportions as to yield a clear solution, is allowed to 
act on tissue material which has been hardened for a long time in alcohol. 
Inorganic sulphur combinations yield the result at once, while the lightly 
bound organic sulphur gives the brown colour of lead sulphide on the 
application of heat. The reaction has been found useful in determining 
some points of importance, as for example the proteid character of a 
number of structures in the protozoa and protophyta, and the presence of 
sulphur in the chromosomes of the nucleus in the dividing cell, a fact 
which indicates that these bodies, contrary to the view of some cytologists, 
are not constituted of pure nucleic acid but rather of a nucleo-proteid. 
(3) Observations on the distribution of organic phosphorus, in the case 
of compounds digestible in artificial gastric juice. These demonstrated 
that the soluble compounds are much more abundant than the insoluble 
ones (7c. nucleins or chromatins) in the cells of the liver, thyroid, 
suprarenals, and pituitary gland. In the latter organ the soluble com- 
pounds are specially abundant, and they appear to constitute also a con- 
siderable portion of the colloid material of this organ. 
(4) The action of different mineral reagents on cellular structures 
hardened in alcohol, under high pressures (8-12 atmospheres), and at 
temperatures between 100°C. and 200° C. This line of work has been 
followed for less than two months, and consequently the results are incom- 
plete, but they are of interest when taken in connection with the results 
of artificial digestion. It is proposed to compare these results with those 
obtained by treating in a similar way the cell juices extracted from fresh 
cells by hydraulic pressure. 
899. RR 
