fae So Sag Es Se ae 
A. W. Wright—Gases in Smoky Quartz. 213 
found to be 18-4 milligrams, in No. 2, 12 milligrams, corre- 
_ Sponding respectively to 18-4 and 12 cubic millimeters at 4°. 
The volume of the quartz in the first instance being 8-25, an 
in the second, 7'41 cubic centimeters, we have for the amounts 
contained in one cubic centimeter of the mineral, 1°63 and 
would indicate a comparative uniformity in the distribution of 
the water, while the amount of the gas varies. But such a 
conclusion is at best doubtful, inasmuch as the darker quartz 
is not as thoroughly broken up by the heat as the,lighter vari- 
ety, and the refrigeration of the tube . was not made 
complete at first, so that some water doubtless escaped with 
the gas uncondensed. 
A small portion of the water removed with a minute pipette 
Was dropped upon red litmus paper, where it produced a strong 
but fugitive alkaline reaction, implying the presence of free 
ammonia. This was confirmed by adding Nessler’s test solu- 
hon to the remainder of the liquid in the end of the tube, in 
which it caused the characteristic yellow coloration, and, in 
While the glass around it and over it lost. its transparency as 
if corroded, similar but very slight action upon the glass 
Where the moist gas had come in contact with it had previously 
en observed. ‘This suggested the presence of fluorine. The 
glass of the tube in which the effect was most marked contained 
Some lead, but the other showed it also to some extent. 
Special experiment with a tube free from lead, which had been 
most carefully cleaned, gave the same result, though in a some- 
What less marked degree. Its appearance would be accounted 
for by the supposition that the water of the cavities containe 
Some hydro-fluo-silicic acid in solution, resulting from the de- 
Composition of silicon fluoride, or, as ammonia was also present, 
om an ammonium compound of the acid. i 
a was mentioned in a preceding paragraph, no evidence 
Ot the presence of a hydro-carbon compound was discovered in 
