Chemistry and Physics. 149 
SrN,O,.(H,O), gives up all its water under the moderate pressure 
of 0°61 at 12°4°; and hence its water molecules cannot be sepa- 
rated in the formula. Zine nitrate ZnN,O,(H,O), showed for 
two of the water molecules a pressure of 0°18 at 16°1°, which fell 
rapidly during the evaporation of the third molecule to 0-025 and 
Bee ELO) ae 
H,O 
(H,O),. By heating this salt to 100°, Graham found that three 
molecules of water were driven off and the residue Zn N,O,.(H,O), 
left. Barium hydrate BaH,O,.(H,O), loses the eighth molecule 
of water under the relatively high pressure of 0°88 to 0°92, then 
five molecules at the pressure of 0°18 to 0°22, then two molecules 
at 0°10 to 0°12 and retains one molecule; so that the formula of 
then became insensible. Hence its formula is 
BaH,0,.H,O +(H,0),. Strontium 
H,O 
f 2 
hydrate SrH,O,.(H,O), losés one water molecule at 0°73 at 17°6° 
and six molecules at the pressure 0°27 at 18°5°, while the last 
molecule remains with the hydrate. Hence this salt has the 
SrH,O,.(H,O) 
(H,O), 
2876, November, 1886. G. F. B. 
8. On the solidification of Hydrogen fluoride, phosphide and 
antimonide.—Hydrogen fluoride, according to OLszEwsky, pre- 
pared by heating dry hydro-potassium fluoride and condensing 
the product in a platinum receiver cooled by ice and salt, solidi- 
fies at —102°5° as a transparent crystalline mass fusing at — 92°3°. 
In the absence of water the liquid does not attack glass. Hydro- 
gen phosphide boils in the vicinity of —86° and solidifies as a 
crystalline semi-transparent mass at —133°5°, beginning to fuse 
again at —132°5°, Hydrogen antimonide, evolved by the action 
of dilute sulphuric acid upon an alloy of two parts antimony and 
three parts of zinc, crystallizes at —102°5° as a snow-white mass, 
fusing at —91°5° to a colorless liquid, which even at the low tem- 
perature of —56° to —66° partially decomposes with separation of 
antimony. It boils at —18°.— Wien. Monatsb. f. Chem., vii 
371-374; Ber. Berl. Chem. Ges., xix, 739 (fef.), Nov., 1866. 
G. F. B. 
4, On the Fluorescence of certain Metallic Oxides, when exposed 
to an Electric discharge in a high vacuum.—Lxcog DE Boispau- 
DRAN has examined several of the metallic oxides by the method 
of Crookes, with a view to determine the character and intensity 
of their fluorescence under these conditions, either alone or mixed 
with other substances. Of these oxides that of manganese is 
remarkable for the variety of the colors it gives, and for the 
characteristic band in its fluorescent spectrum. Neither manga- 
nese sulphate nor manganese peroxide perceptibly fluoresces after 
calcination, when alone. But mixed with calcined calcium sul- 
composition of this hydrate is 
formula +H,0.— Ber. Berl. Chem. Ges., xix, 2874— 
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