215 
ON THE PURIFICATION OF AMMONIA CAL SALTS FROM 
GAS-LIQUOR SO AS TO UTILIZE THEM FOR PHARMA¬ 
CEUTICAL PURPOSES. 
BY WENTWORTH LASCELLES SCOTT, E.C.S., ETC. 
In offering, somewhat prematurely, a few remarks upon this subject, I 
do so merely with the view of eliciting the results arrived at, or opinions 
held by other inquirers, as a means of more thoroughly ventilating the entire 
question in the time to come. 
The extraction and fixing of ammonia-salts from all varieties of coal-distil¬ 
lates is so well understood, that any mention of these commercial processes, 
which are conducted upon an enormous scale all over the country, would be 
quite superfluous. The one point w r ith which we have to deal is, that how¬ 
ever often these gas-ammonias,—say the chloride and sulphate of ammonium, 
—are recrystallized (within, of course, the stern commercial limits of what 
will pay), they are still contaminated with a persistent tarry odour or 
“ twang,” which renders them unfit for the preparation of “ Liq. Ammon. 
Acetatis,” etc. 
Long-continued boiling with excess of acid, of course, drives off the more 
volatile hydrocarbons, but fails to remove those tarry and resinoid matters 
whose presence is most objectionable. 
I have lately adopted a process which certainly has in many instances ad¬ 
mirably fulfilled its purpose ; whether it will answer equally well for all the 
varieties of ammonium-salts derived from coal, must be determined by more 
extended experience. Anyhow, the method succeeds perfectly in numerous 
cases, and has the merit of inexpensiveness at least. 
To the solution of roughly-purified sulphate of ammonium some persul¬ 
phate of iron is added (or, what is the same thing, some iron-rust, or any 
convenient form of old, oxidized iron, is dissolved in the acid solution), and 
the whole is brought to the boiling-point. A small quantity of a dilute solu¬ 
tion of permanganate of potassium is next added in gradually, until a little of 
the liquor, filtered and neutralized with pure alkali, when cool, no longer de¬ 
colorizes a drop of the permanganate solution. 
At this stcige, a slight excess of cilkcili is cidcled. to precipitate the whole of 
the metallic oxides, which carry with them all that remains of the contami¬ 
nating matters. The liquor may then be safely employed for the preparation 
of the acetate or other salt, which will then be free from all objectionable 
odour or flavour. 
The quantity of permanganate required is extremely small. 
ON THE VARIATIONS IN THE QUALITY OF COMMERCIAL 
CHLORINATED LIME. 
BY WENTWORTH LASCELLES SCOTT, F.C.S., ETC. 
(.Second Report.) 
I have but little to add to my former observations upon the above subject 
{vide proceedings of the Conference, Norwich meeting), but beg to offer some 
farther analyses of chlorinated lime, fourteen samples ot which 1- have ex¬ 
amined since the last meeting. ' 
Communications received from manufacturers of the bleach, as well as 
from some large consumers, show that several in each class would be phased 
