176 
MINERALOGY: G. P. MERRILL 
From (1) it follows that antitoxin destruction may take place with or without 
protein splitting. 
3. In solutions containing trypsin and 0.5% sodium carbonate the results 
were the same as in (2). 
4. Tetanus antitoxin in 0.2% hydrochloric acid was completely destroyed 
in three or more days. During this time no significant chemical changes in 
the proteins were detected. 
5. In neutral solutions pepsin did not affect the antitoxin. 
6. In pepsin-hydrochloric acid, proteolysis and antitoxin destruction pro- 
ceeded simultaneously. 
These results tend to indicate that tetanus antitoxin is a substance of 
non-protein nature. But the stability of the antitoxin is so dependent upon 
that of the protein to which it is attached, that whenever the protein molecule 
is split, the antitoxin splits with it. 
The experimental details are given in the Journal of Agricultural Research, 
1918. 
1 Homer, A., J. Hygiene, London, 15, 1916, (388-400). 
2 Rosenau, M. J., and Anderson, J. F., Hygienic Lab. Bull., No. 43, 1908. 
TESTS FOR FLUORINE AND TIN IN METEORITES WITH NOTES 
ON MASKELYNITE AND THE EFFECT OF DRY 
HEAT ON METEORIC STONES 
By George P. Merrill 
Department of Geology, United States National Museum, Washington 
Communicated by E. W. Morley, April 29, 1918 
The following is a partial report on results obtained in continuation of 
work under a grant from the J. Lawrence Smith Fund of the National Academy 
of Sciences. 
1. On Fluorine in Meteoric Stones. — So far as I am aware the occurrence 
of fluorine has never been recognized in meteoric stones. Meunier 1 records 
its presence as doubtful. Fletcher in his Handbook does not mention it at 
all, nor is it mentioned by Cohen nor by Lockyer in his Meteoritic Hypothesis 
as one of the elements even recognizable by the spectroscope. Nevertheless, 
the occurrence of a calcium phosphate has often suggested its possible pres- 
ence, and the wide distribution of this phosphate in meteoric stones, which I 
have shown of late 2 seemed to warrant further tests, particularly as new and 
more refined methods for its detection had been discovered. Opportunity 
for these tests was recently afforded by Dr. E. T. Wherry when engaged upon 
the investigation of some fossil bones for Dr. Hrdlicka in the Museum lab- 
oratories. The method consists in the digestion of the material in concen- 
