78 M..C. Lea on New Combinations of 
agi whether of soda, ammonia or potash, except under cir- 
nees of great dilution, especially if allowed to repose for 
24 rivera: 
That picrate of ammonia os picrate of magnesia give the 
same results, but in a less degr 
hat picrie acid is therefeve wth unreliable as a test for 
potash; the results obtained being such.as would tend rb Se 
to mislead those who are not extrem mely familiar with t 4 
pearance of the precipitates, and that in some eases. the resulli 
are so deceptive that even eyes most familiar with these reactions 
might be —— for example, in the result-obtained above by 
testing a solution ’ containing 1 per cent. sulphate of ammonia 
with solution of picrate of soda. In this case a eetaiaileaation of 
aoe ve ammonia was obtained perfectly eintulating that of the 
otas : 
. Piano: acid is in fact a better test for soda, than for pot 
ash, because with a soda solution it gives a precipitate which + 
redissolved by heat generally (but not always) givesa character. 
istic spherically radiated, bright canary yellow crystallization, 
wares the precipitate obtained from a a potash solution can 
‘be positively distinguished by its appearance from that 
an ammonia solution, and we have just seen thata — 
Ration: containing ,1, of sul hate of ammonia or even less, is 
capable of producing such a precipitate. 
see Feb. 23d, 1860. 
« 
ae 
SO 
2 
) 
: 
~ ~ Awe econ a Series of New Chmabinations 3 Ammonia, Picrie : 
_. Acid and Metallic Bases ; by M. C 
[Read bitteae the Am. Assoc, for the Advancement of Sci., at Newport, Aug. 1860.] 
IN a paper published i in this Journal, aa xxvi, 379, for 1858, 
described tw genase picric and ammonia with — 
ng che in a state of tolerable 
*. purity. Since then T have found that many other metals im . 
compounds o ar nature, and have succeeded in obtaining — 
several of hae sufficiently ints for ap a analysis. — 
“results obtained are given brie vos So are in 
progress and I hope to communicate 
When a metallic salt is precipitated oe setae a and a lange 
excess of the precipitant added, a moreor less complete solotion: 
of the precipitate is frequently ‘obtained, especially if a consider- 
= quantity of ammoniacal salt be p resent. I have found that. 
these ammoniacal solutions when caer with an alcaline pirate,” 
for the most part yield an immediate precipitate con 
