of course, become anhydrous on exposure to dry air) ; the results 
then become : — 
Oxygen. 
Ratio. 
Calculation. 
Lime, 
. 15-55= 4-44 
3*08 
3 CaO 
84 
15*46 
Soda, 
. 5-61= 1-44 
1 
NaO 
31 
5*77 
Water, 
. 19*72 = 17'52 
12* 16 
12 HO 
108 
20*11 
Boracic acid, 
. 59*10 = 40-47 
28*10 
9 BO, 
314T 
58*48 
99*98 
537*1 
100*00 
— corresponding to the formula, 
NaO, 3 CaO, 9 BO, + 12 HO. 
I am very well aware that it is unsafe to base a formula upon a 
single analysis, especially of a mineral substance, and most espe- 
cially after making deductions as above, and I cannot, in this case, 
insist on the one brought out, but it is not anomalous. We find 
rather complex combinations both in the natural and artificially 
formed compounds of boracic acid ; thus, 
Hydroboracite,* = 3 CaO, 4 BO, + 3 MgO, 4 BO, + 18 HO, and 
Larderellite,* = NH 4 0, 4 BO, + 4 HO ; 
while Laurent describes*]* a salt =5 NaO, 24 B0 3 + 52 HO, and 
Hose onej = 3 CaO, 5 B0 3 when ignited ; and it is a little curious 
that the formula given above includes the soda compound corre- 
sponding to Larderellite and the salt of Rose — 
NaO, 4 BO, + 3 CaO, 4 BO, + 12 aq. 
I mentioned that the mineral presented no appearance of crystalline 
structure to the naked eye. Not having at hand, at the time I was 
at work upon it, a sufficiently good microscope, I sent a portion of 
the mineral to Professor Robb, of the University of New Brunswick, 
at Fredericton, with a letter stating my results and my doubt as to 
the substance being crystalline. I received this answer — 44 In spite 
of your odd formula, the mineral just as I got it, untouched and 
unwashed, is perfectly crystalline in every particle. A good power 
is required; but with a magnifying power of about 350 diameters 
there is no difficulty, the form comes out as sharp as possible. The 
crystals are excessively thin translucent tables or plates. They 
have a rhombic outline, and the angles probably = 80° or more, 
* Dana’s Min., 4tn ed., 394, 395. 
t Liebig und Kopp’s Jahresbericht, 1849, p. 226. 
J Ibid., 1842, p. 313. 
