Chemistry and Physics. 109 
Ta,0,.M9, and the second the formula 3Ta,@,.4M6: the tantalates 
of soda and potash belong to this last type and. crystallize well. The 
oxyd and sulphid of tantalum described by Berzelius and others have 
ts aed the formulas Ta@, and TaS,. Chlorid of tantalum has the 
for 5; the calculated density of its vapor is 12°84, while De- 
ville and Troost find 12°42. Tantalic acid not ignited dissolves easily in 
fluohydrie acid and forms soluble and erystallizable salts with other fluo- 
rids, but it does not appear that there is a class of oxyfluotantalates cor- 
are to the oxyfluoniobates. The fluotantalate of potassium, 
F 
with the corresponding fluoniobate. When boiled for a long time with 
water the salt changes to an insoluble body having approximately the 
formula Ta,0,+-2(2KF.TaF,), which may, ae be only a mixture. 
The formation of this insoluble compound s the means of detecting 
Two yee ey of sodium have respectively the formulas TaF 2NaF 
+H,0 and TaF,3NaF. The other salts described are TaF,,2NH,F, 
TaF ,, 2ZnF-+7aq, and TaF,,2CuF+4aq. In our first notice of Me 
rignac’s researches we have stated that that — had detected in nio- 
bite a small quantity of an acid which might prove to be new. Further 
renee has, however, shown that re is titanie acid.— Bull. de la 
76 imique, Aug. 1866, pp. 118 and 11 Ww. G. 
On the preparation of iodhydric se phosph oric acids,—PETTEN- 
“ea has given a very elegant noes of Liebig’s process for the 
preparation of iodhydric acid and alkaline iodids, an has further ex- 
. Aaa Sata 
product. To half an ounce of common phosphorus in twelve ounces of 
distilled water at 60° or 70° C. one ounce of iodine out of eight ounces 
is to be added. The whole is to be stirred and the liquid poured off 
from the phosphorus and iodid of phosphorus upon the remaining seven 
ounces of iodine contained in a separate vessel. The solution of iodine 
as thus obtained is to be poured back upon the phosphorus and the alter- 
nate process repeated until all the iodine is dissolved and has come in 
contact with the phosphorus. The red-brown liquid last obtained be- 
comes almost colorless after a short time, and there remains only a hee 
0 
of potash the acid yields on = and crystallization a pure iodid 
in perfectly colorless Pg The contents of the retort are to be 
t 
ounces of nitric acid of 1-20, added in small portions at a time until, on 
addition of pure acid, nitrous acid fumes are no longer evolved. The so- 
