4A Improvements in Physical Science [JAN. 
the salt. Sulphuric acid and the alkalies throw down a white pre- 
cipitate from the solution of this chlorate. 
(5.) Chlorate of Copper.—Peroxide of copper dissolves readily 
in chloric acid. ‘The solution is green, and always contains a slight 
excess of acid. It crystallizes with difficulty, because the salt is 
deliquescent. It melts on burning coals, producing a green flame. 
A paper dipped in the solution of this salt, and held near the fire, 
burns with a fine green flame at a temperature not so high as would 
be sufficient to burn the paper alone. (See Ann. de Chim. xcv. 
113.) 
5. Phosphates.—Berzelius has lately made numerous experiments 
on the analysis of the phosphates, in order to determine the com- 
position of phosphoric acid. (Anp. de Chim. et Phys. ii, 151.) 
I shall here give the facts which he has ascertained. 
(1.) Phosphate of Barytes.—Barytes and phosphoric acid unite in 
three portions, forming a neutral salt, and two salts with excess of 
acid. The neutral salt is obtained by mixing phosphate of am- 
monia with muriate of barytes, Berzelius analyzed it by dissolving 
it in nitric acid, and throwing down the barytes by means of sul- 
phuric acid : 7°5 parts of the salt furnished 7°798 parts of sulphate 
of barytes. Hence it is composed of 
Phosphoric acid .....- ies ES orcs a LOO 
BIVtGSh iis pe pitietan ». +» 68:2 ...,. 214°46 
100°0 
Biphosphate of barytes was formed by dissolving the neutral 
phosphate in phosphoric acid, filtrating the liquid, and evaporating 
it slowly in a platinum capsule. Crystals gradually formed, which 
were separated, and dried upon blotting paper. This salt contains 
water of crystallization, and has a good deal of resemblance to 
crystallized muriate of barytes. Its taste is slightly acid; but in 
other respects similar to that of the muriate. When heated, it 
swells, and forms a porous mass, like burned alum. It is decom- 
posed by water, which removes the excess of acid. — Its constituents 
are— ; 
Phosphoric acid ........ 42°54 .... 100°00 
BOOT VUES 0. ie sss sodioajaies AG AG ee WEL 
WVatere osteo em eee on 11°00 
100°00 
Thus we see that it contains just twice as much acid as the neutral 
phosphate. 
Sesquiphosphate of Larytes (phosphate acidule de baryte of Ber- 
zelius) is obtained by pouring a solution of the preceding salt into 
alcohol. A bulky precipitate falls, which, when washed with 
aleohol, and dried, forms a light white powder. It was found 
composed of 
