— 82 
The ferric and aluminic phosphates were thrown down 
from the filtrate by means of ammonia, and acetic acid 
added to dissolve the other phosphates. This precipitation 
had to be repeated at least three times to get rid of baric 
and calcic phosphates. There was not maganese enough in 
any sample analyzed to come down with ferric and alumi¬ 
nic phosphates in sufficient quantity to be detected. 
The ferric oxide was separated by means of citric acid 
ammonia and amnionic sulphide. If the precipitate < \ ! 
phosphates is not heated too strongly, even partial* fusio k 
must be avoided, their solution in hydrochloric acid is easily .1 
effected, and the separation is easily performed. 
PHOSPHORIC ACID, MANGANESE, LIME AND MAGNESIA. 
A quantity of pure ferric chloride, sufficient to com¬ 
bine with all the phosphoric acid, was added and then, 
if the solution was not too acid, solid sodic acetate 
sufficient to convert all the bases into acetates, and the whole 
evaporated to dryness on the water-bath. If the solution 
was too acid, it was partly neutralized with sodic carbonate 
before the addition of the acetate. The dry mass was 
moistened with acetic acid and boiled out with water. As 
a rule,I do not wash this precipitate thoroughly,but dissolve 
it in hydrochloric acid and evaporate the second time with 
the addition of sodic acetate. The precipitate contains 
neither manganese, lime nor magnesia and the solution is 
free from iron and alumina, from which no trouble is experi¬ 
enced in precipitating even traces of maganese h>y bromine 
water, and has the further advantage of being small in vol¬ 
ume. The lime was precipitated as oxalate, with the ordi¬ 
nary precautions, to obtain its complete precipitation. I 
allowed it to stand as long as at all convenient, washed and 
dried it partially and ignited it in a platinum crucible or dish 
until all the oxalate was destroyed; it was then brought into 
solution and reprecipitated as oxalate. I his precipitate was 
free from magnesia. The filtrates containing the magnesia 
were evaporated to a convenient volume and the magnesia 
thrown down by ammonic phosphate ; this precipitate was 
purified by solution and reprecipitation. A nitric acid so¬ 
lution of the precipitate of ferric oxide, containing the phos¬ 
phoric acid, was obtained either by dissolving it in nitric 
acid directly, or by first dissolving it in hydrochloric, acid, 
precipitating by ammonia, washing and then dissolving it 
.in nitric acid. The latter method will be found the shorter, 
as a rule, and more satisfactory. The phosphoric acid was 
thrown down from this solution by ammonic molybdate, the; 
precipitate washed with dilute nitric acid, dissolved in am- 
