Physics and Chemistry. 887 
ing the difference in the sages 0g of heat ee by their 
oxydation. In aa manner it was found that amorphous silicon 
in ecoming crystalline evolves 290 units of heat per gram, or 4060 
a equivalent ( Veit Yah Comptes Rendus, \xx, 252. Ww. @ 
3. ome remarkable spectra of compounds of z and 
the sepa’ of uraninm.—Mr. Sorsy has found that the remarkable 
absorption bands exhibited by rns ne png of zircon and 
which he had attributed to the presence of a new metal—Jargo- 
nium—are in reality due se uranium, W. hich, mie certain cireum- 
while the zircons exhibit pried Siow ack fae fourteen 
of which are quite distinct, together with other taster lines and a 
broad black band extending from the red end, so that nearly all 
oecur in that part of the spectrum which is entirely free from bands 
in the other uranic ina a Mr. Sorby has detected in some 
“ircons erbium, di¢ idymi ttrium and another substance which 
exists in such small iytaation that the author has not been able to 
decide whether it is a new earth or not. In fact the spectral anal- 
) 
as that — by the presence of a trace of uranium. There is 
therefore at present no evidence that secs contain any new 
metallic se ae Chemical News, Feb. 18, 
se ‘ 
selpane of zinc and cadmium thus formed iteellpciad tem te 
to the formulas 4nSO,+10NH, and €d50,+6NH,. In like 
ner calcic and strontic chlorids unite wit th ammonia to form 
©aCl _+8NH, and SrCl, +6NH, ; hot boric chlorid does not unite 
ith ammonia. By heating the ‘compoun rmed in vacuo, the 
oon of the ammonia may be measured. Cadmic sulphate gave 
1¢ following results, care being taken after each experiment to 
expel the gas which fills the apparatus: 
Temperatures. Tensions. 
48°°5 36am 
51° 439™™ 
51° 
100° (mean of 6) _=—‘1366°3"™ 
The salt remaining in the tube consisted of €450,+2NH, and 
_ 88ve off no more ammonia at 100°. The author afore that the 
cadmic salt should be regarded as Leek 2NH,)4NH, and finally 
that the pulverulent compounds formed always “absorb a little am- 
