April 22, 1871.] 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
845 
not deep green, crystals; it should give a nearly 
white or light blue precipitate with yellow prussiate 
of potash. It should also give no precipitate with 
sulphuretted hydrogen, which would show its free¬ 
dom from copper. A better test for copper is to dis¬ 
solve some of the crystals in distilled water, and 
immerse in the solution a clean knife-blade ; if 
copper is present, it will be deposited as a metallic 
coating upon the iron. 
SULPHO-CARBOLATES. 
BY T. H. HUSTWICK. 
From communications to this and other journals on the 
preparation of some of the above salts, I have gathered 
that the formation of sulpho-carbolate of zinc is best ac¬ 
complished by a process of decomposition or displacement. 
In a late number of this Journal (No. 39) is given a pro¬ 
cess for the preparation of this salt by decomposing sul¬ 
pho-carbolate of lead by metallic zinc; doubtless the 
salt of zinc thus formed is of great purity, but is it not 
possible that a salt of equal purity may be obtained by 
direct combination, saving both time and trouble F My 
own experience leads me to suppose that it may. I have 
made considerable quantities of sulpho-carbolates, and the 
modus opcrandi followed by me has been, in its essentials, 
that recommended by Mr. C. H. Wood in this Journal 
(Yol. X. 2nd ser. No. 7); this process, however, gives a salt 
more or less coloured and less crystallized than when pure. 
Where one of the alkalies or alkaline earths is the base, 
nothing more is required than to evaporate the neutral 
solution so far as to produce a good crop of crystals ; these 
are to be well drained and redissolved for a second crys¬ 
tallization. For the zinc salt I have saturated the di¬ 
luted acid with the oxide, evaporating the solution till, 
when quite cold, a nearly solid mass of crystals is left in 
the bottom of the basin : this reddish-coloured magma is 
well broken up and allowed to rest a short time, wdien 
the supernatant liquor may be removed, the remainder 
placed in a calico cloth and strongly pressed, by which 
a further quantity of red mother-liquor is got rid of, 
leaving a cake of sulpho-carbolate nearly pure ; this, 
■when again dissolved, filtered and sufficiently evapo¬ 
rated, yields the salt in a state of purity far surpassing 
any other sample I have ever seen. As the expressed 
cake is so nearly pure, almost the whole of it may be re¬ 
covered by further evaporation. This procedure applies 
equally to iron and copper. To obtain the copper-salt, 
the diluted acid is saturated with freshly-prepared moist 
carbonate of copper, producing a beautiful intensely green 
solution, which, no doubt will make an excellent colour 
for druggists’ show-bottles. The crystals, when largo, 
arc a brilliant blue, and form clusters of great beauty, 
but difficult to obtain as single crystals; when small, 
they are green, probably from containing less w r ater of 
crystallization. 
The iron salt was obtained by the action of the acid 
on fine iron wire; the colour of the crude solution i3 a 
most intense violet, and, like that of copper, would doubt¬ 
less make a good colour for show-bottles. The expressed 
cake, though almost white, when dissolved, reproduces 
the characteristic violet in almost its original intensity; 
the crystals produced from this solution are violet-green, 
the green predominating; before their removal from the j 
evaporating basin, they should be carefully washed with 
ice-cold water by means of a syringe, in order to free 
them from the coloured mother-liquor which adheres 
with great pertinacity. A peculiarity of this salt is, 
that a freshly prepared solution is almost colourless, and 
without a trace of violet, but as it absorbs oxygen, per¬ 
oxide of iron is precipitated, the violet tinge once more 
appeai-s, and increases in intensity till it almost equals, 
in that respect, the crude solution. 
These salts are all easily prepared, are very stable, and 
as they crystallize from pure solutions with great facility, 
and into regular geometric forms, they make capital show'- 
objects. Some crystals of the calcium salt that I now have 
are perfect rhombs. The way in which all these solu¬ 
tions, during the progress of crystallization, climb up 
and over the sides of the basin, by the force of capillary 
attraction, is rather astonishing, unequalled, as far as my 
observation goes, by any other compound; it is rather a 
nuisance, but may be completely prevented by slightly 
greasing the inside edge of the vessel. Into the chemical 
part of the question it is not my purpose to go, but the 
remarkable changes exhibited by some, at least, of the 
sulpho-carbolates, under the action of high temperatures, 
shows there is room for further investigation. Exposed 
to the heat from a Bunsen’s burner, the soda and potash 
salts exhibit all shades of colour from pale pink to in¬ 
tense purple; and afterwards placed on the glowing' em¬ 
bers of a bright fire, combustion takes place in a very 
similar manner to the old Pharaoh’s serpents, leaving an 
ash equally bulky and eccentric, 
AN ALKALOID FROM CINCHONA BARK HITHERTO 
UNDESCRIBED. 
BY DAVID HOWARD, F.C.S. 
In experimenting upon impure crystallizations of qui¬ 
nine salts obtained from the mother-liquors of the manu¬ 
facture of sulphate of quinine, I have occasionally been 
perplexed by an unusual loss in recrystaliizing, which 
the mechanically adhering mother-liquor did not seem 
to account for. 
A more careful examination of some of these sub¬ 
stances show's that the cause, in some cases at least, is 
the presence of an alkaloid hitherto undescribed, the ex¬ 
treme solubility of the salts of which, both distinguishes 
it at once from the cinchona alkaloids already knowm, 
and renders it very difficult to separate from the un- 
crystallizable quinoidine. 
The most convenient method of obtaining it is to 
purify the alkaloids contained in the mother-liquor front 
the recrystallization of such impure products as I have 
mentioned, by solution in ether, and after evaporation of 
the ether to dissolve wdth oxalic acid in as small a quan¬ 
tity of water as possible, and allow it to crystallize. 
The oxalate thus obtained may be purified by recrys¬ 
tallization from water, with addition of animal charcoal, 
but I have never been able to free it entirely from a 
yellow colour. 
The most satisfactory salt for analysis is the platino- 
chloride, which is prepared in the usual manner; it is 
almost insoluble in water or in cold hydrochloric acid, 
but soluble wfith difficulty in hot strong acid; it forms a 
crystalline powuler by precipitation, and well-defined 
crystals by solution in acid. 
The analysis shows that it is isomeric wdth the platino- 
chloride of quinine, but anhydrous, instead of containing 
one atom of water of crystallization, given off at 120°, as 
does the salt of quinine. 
The ultimate analysis for w'hich, as well as for the 
other combustions which I shall have to mention, I am 
indebted to the skill of Mr. FJuxley and Mr. Gray,_ of 
the Royal College of Chemistry, gives the followfing 
results:— 
C. H. Ft. 
Experiment I. . . 32'67 3-67 26'63 
„ II. . . 32-67 3-82 26-62 
Gerhardb’s formula for the anhydrous platino-chloridc 
of quinine, C. 20 H. 21 N 2 0. 2 , 2HC1, Pt Cl 4 requires 
C 32-60 H 3-53 Pt 26 76 
The salt taken for analysis was precipitated from a 
hot acid solution, and w r as a distinctly crystalline 
powder. 
The composition is the same whether it bo precipitated 
cold in a neutral solution, or crystallized from a strong- 
acid solution, as the following results will show :— 
