444 F. H. Storer—Ammonia a contaminant of Sulphuric Acid. 
Portions of the distillates from the sulphides of sodium, 
potassium and iron, on being tested with Hinbrodt’s reagent, 
for the sake of control, gave strong reactions for ammonia. 
In order to avoid any confusion that might arise from colora- 
. tion of the Nessler reagent by sulphuretted hydrogen, the 
following modifications of the ordinary process were employe 
in testing sulphur and the sulphides. In the case of sulphide 
of potassium and sulphide of sodium, the weighed substance 
was dissolved in about half a litre of pure water, free from 
ammonia, the solution was distilled and a quarter litre of distil- 
The distillate was acidified with a few drops of sulphuric acid, 
boiled until sulphuretted hydrogen had ceased to come off an 
then redistilled with milk of lime, the ammonia in the new dis- 
tillate being determined with Nessler’s reagent in the usual way. 
In the case of sulphur and sulphide of iron the finely pow- 
dered, weighed substance was distilled with milk of lime, the 
distillate was acidified and boiled to expel sulphuretted hydro- 
gen and finally redistilled in the manner just described. 
Oxalic acid, “tertium depuratum” from Marquart, 20 
grams gave 0°0003 gram of ammonia,------- ---- ---- 0700150 
Tartaric acid, from Marquart, 10 grams gave 0:0001 
gra 
0°00100 
0°01200 
AIEEE SEL TEE ON Se RT 0700055 ; 
that is to say, rather less than might have been inferred from 
the fact that ammonium compounds accompany boracic acid = 
the Tuscan lagoons (see Gmelin’s Handbook, ii, pp. 97, 99) 
Bechi, Wagner's Jahresbericht, ix, 855; Vohl, ibid. xu, 205, 
and ibid. (N. 8.) i, 210.) 1 
Though the figures in the foregoing table may seem smal 
or even insignificant to persons unaccustomed to us Nee 
test, they are really large in several instances and noteworthy 
in all. It should be understood, moreover, that in working 
from the 
ed and to 
avoid the ammonia of the air. It is hardly necessary t0 bei 
scat 3 had been im- 
ported and which had never been opened until the time of - 
plying the test, but it is noteworthy that this precautl 
