306 Scientijic Intelligence. 
4, On Phosphorus Tetroxide.-—Tuorre and Turron have 
studied the products obtained by the slow combustion of phos: 
phorus in dry air. If these products are aspirated through glass 
tubes heated by steam, they are free from admixed phosphorus. 
A quantity of these mixed oxides was transferred to a tube pre- 
viously filled with dry carbon dioxide, the end of the tube was 
drawn out, attached to a Sprengel pump, carefully exhausted and 
sealed. On heating it to about 290°, the white mass appeared to 
change; a considerable amount of the orange-red suboxide was 
seen to form, and at some distance beyond was a sublimate of 
clear, transparent -and highly lustrous crystals, which could be 
heated to 100° without change, their edges remaining perfectly 
sharp. On heating to 180° in a sulphuric acid bath, they volatil- 
ized and re-condensed just above the level of the acid. They 
polarized light powerfully and are probably orthorhombic in 
form. The crystals are extremely deliquescent and are dissolved 
instantly by water with considerable evolution of heat, forming 
an acid solution. This solution precipitates silver nitrate solu- 
tion, the white precipitate blackening rapidly. It also reduces 
mercuric to mercurous chloride, but decolorizes permanganate 
only very slowly. With magnesia mixture, it gives at once a 
precipitate of ammonium-magnesium phosphate; and the filtrate 
which contains magnesium chloride in excess, gives, after stand- 
ing for some time, an abundant precipitate of phospho-molybdic 
acid. Hence this solution contains both phosphoric and phos- 
phorous acids. ‘To fix the composition of the crystals, weighed 
quantities were allowed to deliquesce in the air, and the diluted 
solution was evaporated with nitric acid, the phosphoric acid in 
it being determined as usual. In two determinations the percen- 
tage of phosphorus present, was 49°09 and 49°46; the calculated 
value for P,O, being 49°20. Hence the authors think the new 
oxide is the tetroxide corresponding to the analogous oxides of 
nitrogen and antimony. The molecular weight however is yet to 
be obtained by means of a vapor density determination.—J/. 
Chem. Soe., xlix, 833-839, Dec., 1886. G. F. B. 
5. On a hydrated Silicium phosphate-—HavTEFEUILLE and 
Mareotrer have obtained a compound, having the formula 
SiO, . (P,O,), . (HO), by evaporating a solution of silica in phos- 
phoric acid at 125°. Globular spherical concretions are formed 
consisting of concentric zones of prismatic crystals, which polar- 
ize light strongly. Water at the ordinary temperature decom- 
poses the new body into phosphoric acid and_ gelatinous sili¢a.— 
C. &., civ, 56-57, Jan., 1887. Gi nares 
6. The Freezing of Aerated Water.—Mr. Grorce Maw has 
made a number of experiments upon this subject and thus sums 
up the experimental results: (1) In a thin ice coating, the upper 
or surface half contains barely a trace of eliminated air, while its 
under or bottom half contained 0:08 cubic inch of air in each 
pound of ice. (2) A surface coating of ice 14 inch thick con- 
tained 0°15 cubic inch of air in each pound weight, while an 
