THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
[October 29, 1870. 
oDZt 
3-r01 per cent, of anhydride as being present. Now, 
theory requires for 2 molecules of water 35'35 per cent., 
therefore this is rather low, which is no doubt due to 
a trace of sulphate of zinc. 
Air-dried sulphite, however, only consumed 2985 
grain-measures of the decinormal solution, the weight 
taken being- 1-918, which corresponds with the ter- 
hydrated salt. Thus, theory Zn" S 0 3 ; 3 H. : 0 would give 
32-16 anhydride, practice gives 32-39. Sul phite which had 
been finely powdered, and submitted to the prolonged 
action of sulphuric acid under a bell-glass, gave a simi¬ 
lar result. We therefore see that the discrepancy ob¬ 
served in different authorities is easily accounted for; the 
composition of the salt varies according to the method 
by which it is dried. It is as follows:— 
Dried in the air, or over sulphuric acid, Zn" S 0 3 ; 3ILO. 
Dried at 100° C.". . . . Zn"S0 3 ; 2H 2 0. 
M. Fordos’ formula is correct as long as the salt is 
dried at 100° C., but not unless this is the case ; whilst 
Rammelsberg- had evidently been operating- upon a salt 
one molecule of water in which had been partially disso¬ 
ciated by heat. The terhydrated salt may be viewed as 
the normal compound, as it seems perfectly stable under 
ordinary circumstances. 
General Properties and Stability. —Sulphite of zinc is 
very insoluble in water at the ordinary temperature. 
500 grains of a saturated solution consumed 82-5 measures 
of the iodine solution, which represented -164 per cent, 
of the hydrated salt. It crystallizes in semitransparent 
prismatic crystals, which are pellucid on recrystallization 
from sulphurous acid. It decolorizes a solution of iodine 
without being acidulated. One extraordinary property 
of the sulphite of zinc is its ready solubility in an excess 
of sulphurous acid. If washed, sulphurous anhydride is 
passed for some considerable time through 1 part of the 
salt suspended in about 3^ parts of water. A solution is 
readily obtained containing about 20 per cent, of sul¬ 
phite, and having- a specific gravity sometimes as high 
as 1-240 to 1-245 at 15° C. 15 per cent, easily dissolves 
in the ordinary sulphurous acid of the Pharmacopoeia. 
When dry, neither the di- nor tri-hydrate sutlers oxi- 
■ dation on exposure to the air. They are, contrary to what 
is stated in the books, perfectly stable salts; however, 
like most of the sulphites when in solution, they suffer a 
: gradual but slow oxidation; and thus its antiseptic 
power. Thus a saturated solution of the sulphite when 
tested with the volumetric solution gave the following 
results,—in each experiment 500 grains were taken:— 
Day of tlie Month. Grain Measures of Vol. Solution. 
8th.82-5 
9th...66* 
10th.50* 
11th.25- 
12th.10- 
On the 15th the sulphurous acid had become converted 
into sulphuric. The saturated acid solution was diluted 
- with water, and tried in a similar manner. The oxida¬ 
tion was not nearly so rapid, and at the expiration of 
fifteen days it had not lost ten per cent, of its strength. 
The saturated acid solution suffers very little change. 
Uses in Pharmacy. —The composition of sulphite of zinc 
would naturally point to its therapeutic uses. It might 
be viewed as a desiccant, antiseptic, astringent and 
caustic (we are now speaking of its external applica- 
tions). As regards the last its insolubility renders it so 
mild that it could be hardly considered under the head 
of a caustic at all, and more nearly approaches the desic- 
• cant, oxide of zinc, in this respect. Its antiseptic pro¬ 
perties, like all the readily oxidizable sulphites, are well 
marked; nor is it, indeed, necessary for it to come in 
contact with acid secretions for its power, in this respect, 
to come into play. It has been tried in some of the 
hospitals, and well spoken of in many cases.* 
* A medical friend, of considerable hospital experience, 
The following formula3 may be suggested:— 
Sidphite of Zinc Lotion. 
Take of 
Finely powdered sulphite of zinc 20 grains. 
Distilled water gxx. 
Digest twenty-four hours, occasionally shaking, and then 
decant the clear solution for use. This lotion should be 
made as required. 
This lotion will contain about I grain to the fluid 
ounce, and might be advantageously used as a cold-water 
dressing- for wounds. 
Acid Sidphite of Zinc Lotion. 
Take of 
Powdered sulphite of zinc 8 grains. 
Sulphurous acid B. P. 5i fluid. 
Mix, and when dissolved add 
Distilled water gi gvij. 
Sidphite of Zinc Ointment. 
Take of 
Prepared lard 5vij. 
Powdered sulphite of zinc 1 w . 
dried at 100° C j ol ‘ 
Compound Sulphite of Zinc Ointment. 
Take of 
Lard giiiss. 
Oxide of zinc 5iij. 
Sulphite of zinc 5i. 
The above ointment has been found most useful as a 
mild desiccant and antiseptic ointment in skin diseases. 
The President said the sulphites were coming into 
very general use, especially the lime, potash and soda 
sulphites; and that one large mode of consumption was 
for brewing purposes, for making- weak beers keep from 
turning sour in summer weather. 
Mr. Cottrill (Shepton Mallet) said that in Somerset¬ 
shire the use of bisulphite of lime for cider was very 
extensive. 
Mr. Tichborne stated that bisulphite of lime was 
much used in the porter breweries of Dublin, and its 
preservative effect was undoubted. However, it was 
open to the objection that some of the nitrogenous com¬ 
pounds of the porter united with the liberated sulphur, 
and when this porter was bottled a fetid gas was deve¬ 
loped. This difficulty did not exist in the case of ale. 
Professor Attfield remarked that the discussion of 
the paper by Mr. Tichborne had somewhat drifted into 
one of its bearings only, but beyond this they must re¬ 
cognize that the paper represented a large amount of 
able and laborious work, for which they were greatly 
indebted to the author. 
The Flax Lints of Commerce under the Microscope. 
BY THOMAS GREENISH, F.R.M.S. 
The introduction of machine-made lint, which dates 
from about 1847, has to a very great extent superseded 
writes as follows :—“ A lotion of the sulphite of zinc proved 
highly beneficial in a case of gonorrhoea, rapidly lessening the 
discharge, and causing but slight pain. From the rapidity of 
the change in the character of the discharge after each in¬ 
jection, it would appear as though it acted not only as an 
astringent, but also as an antiseptic, causing decomposition in 
the pus, with which it came in contact; and subsequently in 
its chronic stage an injection, formed of 1 grain of sulphite 
to the gi, held in solution by a sufficient quantity of sul¬ 
phurous acid, caused a complete cure, without pain or incon¬ 
venience. It requires further experience before pronouncing 
definitely on its merits ; but there is sufficient evidence of its 
usefulness to warrant extensive trial in other cases. It would, 
no doubt, make an excellent collyrium (without the acid) in 
purulent ophthalmia, and a stronger solution might be used 
in ulceration of the mouth and gums. The solution of 2 grains 
to gi of the acid solution was tried with excellent results to 
lessen the fetor in a case of extreme suppuration from a 
burn. In skin diseases, especially those of a parasitic origin, 
sulphite of zinc would probably prove invaluable.” 
