806 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS, 
[April 6, 1872. 
Crystallized Iodide of Lead. —The author proposes to 
take advantage of this fact for the preparation of crys¬ 
tallized iodide of lead. This compound is usually ob¬ 
tained by dissolving the iodide in an excess of water 
and evaporating; hut the operation is a tedious one, at 
least ten litres of water being required to obtain thirty- 
grams of crystals. The method he suggests is to boil 
together— 
Distilled Water. 100 grams. 
Acetate of Sodium.160 „ 
Acetic Acid.A few drops. 
To this solution a paste consisting of eight grams of 
Iodide of lead mixed with a little water, is to he added 
in small quantities at a time, stirring continually. When 
all the iodide is dissolved, the solution is left to cool. 
After twelve hours a small quantity of cold water is 
added, and then larger quantities, until the whole of the 
acetate is separated from the iodide. The crystals of 
the iodide are then collected on a filter, washed, dried 
and preserved in bottles. 
Detection of Impurities. —The author also points out that 
this property allows of the recognition and quantitative 
estimation of the chromate of lead frequently present as 
an impurity in the iodide. For this purpose 0 - 5 grams 
of the suspected iodide may be heated for a quarter of 
an hour in a saturated solution of sodic acetate, acidu¬ 
lated by a few drops of acetic acid. At the end of that 
time, the whole of the iodide will be dissolved and the 
chromate of lead, if present, will be deposited on cooling. 
This may be separated by a tarred filter, washed, dried 
and then weighed. M. Tommasi states that he has thus 
been enabled to detect with great facility *002 gram of 
the chromate, which he had previously mixed with 0-5 
gram of the iodide. 
Glycerole of Iodide of Lead. —Glycerine, which only 
dissolves traces of iodide of lead, will dissolve a con¬ 
siderable quantity when mixed with acetate of sodium. 
The author therefore suggests that a glycerole might be 
prepared containing the iodide in solution, not in sus¬ 
pension, that would be more active than the ointment, 
and he expresses an opinion that the acetate of sodium 
present would not interfere with its use for the purposes 
to which the ointment is usually applied. It may be 
made from— 
Saturated solution of acetate of sodium . 15 c. c. 
Glycerine.25 c. c. 
Iodide of lead.0'4 gram. 
Rose water.A few drps. 
These ingredients should be rubbed in a porcelain 
mortar until the iodide of lead has entirely disappeared. 
Should the glycerole be too thick, it may be diluted with 
a little water. 
It should be borne in mind that though iodide of lead 
dissolves freely in hydriodic acid, the alkaline iodides 
.and chloride of ammonium, in those cases well-defined 
double combinations are formed ; for instance— 
Pb"I 2 + IH = Pb" { jIH 
TINCTURE OF PERCHLORIDE OF IRON. 
BY JOHN H. WILSON. 
The above tincture, prepared according to the directions 
in the present Pharmacopoeia, cannot be kept for even a 
short space of time without the formation of a consider¬ 
able precipitate of oxychloride of iron, which, besides the 
loss of strength that it causes, presents a most unsightly 
appearance in the bottles in which the tincture is pre¬ 
served. Many chemists therefore retain the use of the 
old London Pharmacopoeia formula, which, if not equal 
in other respects, has a transparent appearance with 
slight, if any, sediment. 
Professor Attfield, in his ‘ Chemistry,’ remarks that 
“ the spirit” in the B. P. tincture “is unnecessary, use¬ 
less and deleterious, for it acts neither as a special solvent 
nor as a preservative, the offices usually performed by 
alcohol; but, unless the liquid contain excess of acid, 
decomposes the ferric chloride, and causes the formation 
of an insoluble oxychloride of iron,” closing his remarks 
by saying that “ the liquor, which is similar in strength, 
is doubtless destined to displace the tincture altogether.” 
Seeing that physicians and medical men generally, 
still continue to prescribe the tincture of iron, and are 
likely to do so, regardless of its instability, it would be 
more satisfactory to have a formula from which a tinc¬ 
ture can be produced, which will remain clear and free 
from deposit for a considerable length of time. I would 
therefore suggest an addition to the B. P. formula of 10 
per cent, of pure glycerine, which I find to answer all 
the purposes of preservation. 
The following would then be the recipe:— 
]pb Liq. Ferri Perch. Ft. ^v. 
Sp. Vini Rectif. ^xiij. 
Glycerin. Pur. 313 . 
Mix the glycerine with the spirit, then add the liquor, 
shake and preserve in a stoppered bottle. 
Thus made, with Price’s glycerine, the sp. gr. is 1’026. 
I have kept a sample thus prepared for upwards of a 
month, and find but a most minute precipitate in the 
vessel, whilst from B. P. tincture kept under similar 
circumstances a large amount has been thrown down. 
The amount of glycerine is not sufficient to make any 
material difference in the taste, and under the circum¬ 
stances it may be considered a justifiable addition. 
THE PUBLIC HEALTH BILL. 
In the course of a speech delivered at Halifax, on 
Wednesday last, Mr. Stansfeld referred to the Public 
Health Bill. He said that it had been prepared with 
considerable care, but with this consciousness, that no 
measure upon such a subject could pass through Parlia¬ 
ment without being made better for the criticisms which 
its publication would bring upon it in Parliament, and 
from the public at large. He had said in the House of 
Commons that he had no jealousy of amendments ; that 
he had even requested suggestions ; and that every sug¬ 
gestion should have the most careful consideration which 
he could give it. Let him say a word upon one clause, 
—the river pollution clause—with regard to which a 
deputation from Leeds had waited upon him that day. 
For several years a Royal Commission had been sitting 
upon the question of the pollution of rivers, and that 
Commission had presented reports, in which it was sug¬ 
gested that the waters in rivers issuing from manufac¬ 
tories should be subjected to certain chemical tests, and 
should not be allowed to be discharged into the stream 
without being subjected to such chemical standard. He 
did not profess to be a chemist; and in considering this 
question, with very great care and thought, he found 
it impossible to see his way to satisfactorily constructing 
a clause that would be able to meet the ever varying 
conditions of the manufactures in various parts of the 
country. He, therefore, gave up the attempt to con¬ 
struct a clause of which he could say to himself, is it 
one by which I can abide ? and he said to himself it was 
only fair and courteous to the Royal Commission that he 
should present to Parliament its proposals ; and in the 
clause to which he referred, subject to certain limita¬ 
tions, he had produced the conclusions and proposals of 
the River Pollution Commissioners. But he invited sug¬ 
gestions on that and on other clauses. He had had de¬ 
putations and suggestions; and he was now in a position 
to say, though not pretending to be a chemist himself, 
that he knew enough to be satisfied that that clause 
would require amendment; and, therefore, he should be 
justified in asking the House of Commons to allow him 
to amend it. 
