1817.} during the Year 1816. 43 
Phosphoric acid ........ 39°13. 2.44 1000 
Merges fo. Saar GO:8 fi istes. ai NODS 
100-00 
By this analysis it contains 14 times as much acid as the neutral 
salt. 
(2.) Phosphate of Lead.—Oxide of lead and phosphoric acid 
unite, likewise, in three proportions, forming a neutral salt, a salt 
with excess of acid, and a salt with excess of base. The analysis 
of the neutral salt puzzled Berzelius for a considerable time. He 
had prepared it by mixing nitrate of lead and phosphate of am- 
monia. At last he found that a double salt had been formed by the 
union of a portion of nitrate of lead with the phosphate of lead. 
He succeeded at last in forming pure phosphate of lead by mixing 
a boiling hot solution of muriate of lead with phosphate of soda. 
This salt was decomposed by means of sulphuric acid: five parts of 
it produced 5°15 parts of sulphate of lead. Hence it is composed of 
Mbhosphoric aeid.zs.s......5.. BA 5's AOU 
Oreste OF Denes ts in60,.,0 ae ac 85 160s aoe 
100 
Superphosphate of lead is obtained by pouring hot muriate of lead 
into biphosphate of soda. ‘The precipitate still reddens litmus, 
after it has heen thoroughly washed with water. Berzelius found it 
composed of 
Phosphoric acid........ 30°269 .... 1000 
Crclde Of leatl. a. 60 sit's s 69°731 °.... 230°6 
So that it is nearly similar in its composition to the sesquiphosphate 
of barytes. 
Subphosphate of lead was obtained by digesting phosphate of lead 
in causticammonia., According to Berzelius, it is composed of 
Phosphoric acid ........-+ 17°48 .... 100 
Oxide of lead............ S2H2ei00; 472 
Now 472 = 314 x 1°5. Thus it appears that the oxide in the 
subphosphate is 14 times as great as that in the neutral phosphate of 
Jead. 
(3.) Phosphate of Silver.—Berzelius was able only to form a 
subphosphate of this salt. When nitrate of silver and phosphate of 
soda, both neutral, are mixed together, the liquid becomes acid, 
while a yellow precipitate falls. This subphosphate, according te 
Berzelius, is composed of 
Phosphoric acid ...... 17025 4:34.49 10000 
Oxide of silver........ 82°975 .... 487°38 
(4.) Phosphate of Soda,—This salt is never quite neutral, acting 
