548 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
[January 6, 1872. 
already that the quantity of ammonia contained in the 
salt was I 5 equivalent. 
The liquid was then decomposed hy caustic potash in 
excess, with the help of a moderate heat, etc., precisely 
in the manner described for the analysis of citrate of 
bismuth. The following numbers were obtained:— 
teroxide of bismuth 1 ■ 170, citric acid 0 - 823. 
The proportion of ammonia being already known, the 
compound may be reconstructed thus :— 
Teroxide of Bismuth 1*170 = 1 equivalent 
Citric Acid . . . 0'823 = 1 ,, 
Ammonia .... 0T22 = 1| ,, 
Water.0T80 = 4 ,, 
Loss. 0-007 ,, 
2-302 
Or in chemical symbols :— 
1|NH 3 ,Bi0 3 . C 12 H 5 O n + 4 HO = 460-4. 
I must say that in this salt I believe the proportion of 
ammonia may vary slightly, according to the mode of 
evaporation; this proportion, however, cannot fall below 
12 - equivalent without causing a decomposition. 
ANALYSIS OP THE DOUBLE CITRATES OF BISMUTH AND 
POTASH, SODA AND LITHIA. 
I believe these combinations have never been men¬ 
tioned nor obtained yet by anybody. Yet, besides their 
interest in a chemical point of view, I think they will 
become of some importance to the medical profession, on 
account of their greater stability than the corresponding 
ammonia salt. For instance, a solution of citrate of bis¬ 
muth and soda may be kept for weeks in warm weather 
without the addition of alcohol; the only change observ¬ 
able is the mouldiness common to all the diluted-solutions 
of citrates, while a solution of citrate of bismuth and am¬ 
monia by the side of it is decomposed in twenty-four 
hours, letting the ammonia escape and forming a heavy 
insoluble sediment which contains almost all the bismuth. 
The citrate of bismuth and soda, and the correspond¬ 
ing potassic salt are obtained easily by adding two equi¬ 
valents of the caustic alkali to one of citrate of bismuth 
suspended in water, moderate heat being applied. They 
require, however, a little more care than the analogous 
ammoniacal combination, for any excess of potash or 
soda is liable to precipitate oxide of bismuth, a decom¬ 
position that ammonia will not effect under any circum¬ 
stances. The double citrate of bismuth and lithia may 
be prepared by adding two equivalents of carbonate of 
lithia to one of citrate of bismuth, heat being applied. 
The following are the formulas of these double salts:— 
Citrate Bismu. and Potash 2K0,Bi0 3 . C 12 H 5 O u +»HO 
„ „ Soda 2 NaO, BiG 3 . C 12 H 5 O n -j-»HO 
„ „ Lithia 2LiO, BiO s . C 12 H 5 O u -i-»HO 
Not having obtained these compounds in scales yet, I 
have not been able to determine the equivalent of water. 
My study of the citrates is far from being completed, 
but I have collected facts enough to justify me in pro¬ 
posing to divide, the different citrates into three classes. 
In the first class I would place all the various simple 
citrates , where the acid is combined with one, two or three 
equivalents of one base. These are so well known, that 
little need be said about them. 
The second class would comprehend the double citrates , 
that is, those salts in which one equivalent of citric acid 
is combined with two equivalents of an alkali and one 
equivalent of another base, generally metallic. The sim¬ 
ple citrate of that base is always less soluble than its 
double citrate. The various double citrates of bismuth 
mentioned in this paper may be considered as types of 
the second class, which contains a great number of them. 
Many are known and mentioned, such as ammonio-citrate 
of bismuth, of iron; potassic citrate of zinc, magnesia, 
etc.; their composition, however, is not stated anywhere 
to my knowledge. 
The third class , or quadruple citrates , as I propose to 
call them, is not so well known,—the only one being, I 
believe, the soluble pyrophosphate of iron discovered in 
1856 by E. Robiquct, my old friend and employer. These 
salts I consider as a combination in which an alkaline- 
neutral citrate plays the part of a base and a peculiar 
metallic salt the part of an acid. I have abundant facts- 
to prove the correctness of my theory, but I will only 
mention that I have already discovered the following 
new combinations which I place in the third class of 
citrates:— Phosphate, hypophosphite, valerianate, ar- 
seniate, sesquioxide of iron and several others, with 
citrates of potash, soda, lithia and ammonia.* 
All those salts are very soluble, they all have a green¬ 
ish colour and present no taste of iron. 
SEWER GASES. 
Epistolary effusions emanating from sanitary lumi¬ 
naries have lately deluged the public journals. If they 
have not succeeded in teaching us how to rid ourselves- 
of the invisible death-dealing compounds arising in the 
form of sewer gases, it should afford their writers some 
satisfaction that their pet theories have been freely ven¬ 
tilated. According to the authorities alluded to, the- 
gas is like Sir John Falstaff’s otter—“you never know 
where to have it.” Allow it to escape in one direction,, 
and fancy you have got rid of it, “up it pops” in an un¬ 
expected quarter, “blows open your traps,” and poisons- 
your habitation. As the tide ebbs and flows so the gases 
surge about, and, from more uncertain and unknown 
causes, appear always ready to attack you at your weak¬ 
est point and carry your defences. A storm will produce 
sudden and unequal commotion attended by uncertain 
phenomena, and it is practically impossible to adequately 
provide against and secure safety from this subtle 
evader of ordinary bolts and bars, by the precautionary 
measures hitherto suggested; even if such suggestions 
offered anything approaching to a sound solution of the 
problem involved. 
It is proposed, in some places, to use trays containing 
charcoal under the sewer gratings, and ventilators, to 
send tall chimneys up into the air, and pipes with outlets, 
above the eaves of houses, and, to use the expression of 
a Government official, to “dilute the gas by admixture 
with the outer air,” in every possible direction. Such 
ideas, if carried out, would be, in fact, calculated to in¬ 
crease the amount of evil, and are a mere paltering with 
a subject of vital importance to the public health. 
Is not the air of London sufficiently foul already ? 
"What is to become of these gases when they get abroad, 
containing, as is supposed, the germs of disease ? Is the 
already-tainted air we are obliged to breathe to be fur¬ 
ther charged with such abominations ? In our climate, 
with its oftentimes heavy atmosphere, the volumes of 
noxious gases carrying these disease-germs would rise 
only to a certain height, and probably spread and extend 
like a pall over the Metropolis. If a gentle breeze were 
to blow from the east, the perfumes wafted into Hyde 
Park and Kensington Gardens would remind the seekers 
of pure air and recreation of anything but the gales from 
“Araby the Blest;” and the inhalation by children 
and others of poisonous germs would thus transform a 
region of recreation into a plague spot. 
That prevention is better than cure is an axiom which 
cannot be controverted. There is a radical remedy for 
the evil, and it seems incomprehensible that public at¬ 
tention has not been more particularly directed to it. 
Why are these sewer gases allowed to form ? We have 
the power of binding find chaining the satanic agency, 
why then let it get abroad to seek whom it may devour ? 
The formation of sewer gases may bo effectively pre¬ 
vented by arresting the decomposition of organic matter 
as it passes through the sewers. No systematic attempt 
[* The solubility of phosphate of sesquioxide of iron in 
citrate of ammonia was noticed in 1859 by Mr. A. F. Haselden 
and the Editor of the American Journal of JBharmacy.\ 
