330 Scientific Intelligence. [APRIL, 
2. Deutoxide of chlorine ; the more recently discovered gas of 
Davy, to which he gave no name. 
3. Chloric acid ; the hyper-oxymuriatic acid of former chemists. 
I am not aware of the terms acide muriatique sur-oxygéné, or 
chlorous oxide, having been employed by chemists. A discussion 
on nomenclature would occupy too much room for this place; but 
I would recommend Mr. Chenevix’s very judicious essay to the 
attention of my correspondent. In the new edition of my System 
of Chemistry I shall be at some pains to give all the synonymes, 
while I adopt the terms that strike me as most systematic.—T. 
VII. On the Mode of detecting Lime in Sugar of Lead. 
(To Dr. Thomson.) 
SIR, 
As it is an object of some importance to the consumers of sugar 
of lead to be enabled to ascertain the state of its purity ; and as the 
sugar of lead of commerce is frequently known to be adulterated 
with acetate of lime; I should be glad to know by what means this 
adulteration can be detected. 
Dr. Henry, in the last edition of his Chemistry,* directs us to 
add to a dilute solution (of the acetate of lead) oxalic acid ; but does 
not this acid precipitate both the lime and oxide of lead, even when 
the solution is extremely diluted? 3° gr. of sugar of lead dissolved 
in 1 oz. of distilled water has, in some experiments made by me, 
afforded a precipitate which, if Iam not very much deceived, was 
all oxalate of lead. 
Iam, Sir, your obedient servant, 
A Constant READER. 
—— 
The most accurate way of analyzing sugar of lead mixed with 
acetate of lime isthe following :—Dissolve 100 grains of it in pure 
water which has been recently boiled: or, if common water be 
used, redissolve the precipitate that forms during the solution, by 
adding a drop or two of nitric acid. Through this solution pass a 
current of sulphureted hydrogen gas, obtained by dissolving sul- 
phuret of iron in sulphuric acid, or sulphuret of antimony in mu- 
riatic acid, till the whole of the lead is precipitated in the state of a 
sulphuret. Then filter the solution, and pour into it carbonate of 
potash or soda. If a precipitate fall, it may be presumed to be 
carbonate of lime. This precipitate must be washed and dried. 
Every 100 parts of it indicate the presence of 1568 grains of ace- 
tate of lime in the sugar of lead. 
There is another method of separating lead from lime in solution 
in the same acid, which is still easier of execution, and which, 
therefore, [ may mention here :—Tartaric acid precipitates lead, but 
it does not throw down lime immediately, provided the solution be 
* Seventh edition, vol, ii, p, 472. 
