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THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. [February 24, 1672. 
ranted Scheele’s strength, and the remaining four B. P. 
strength; and whether we take the one or the other the 
results are alike unsatisfactory. We have in both cases 
an acid not mueh above half the proper strength, whilst 
all the others fluctuate betwixt the two extremes, and 
none are exactly of a proper standard strength. It will, 
I think, be granted from the foregoing table and re¬ 
marks generally that a personal examination of every 
sample, not only introduced into the stock of the phar¬ 
maceutist but also of all kept any time in stock, is abso¬ 
lutely necessary. 
Saccharine Carbonate of Iron. —This is another sub¬ 
stance I have been paying some little attention to lately, 
havihg at first had my attention drawn to it from the 
striking difference in colour and general appearance of 
the different samples which came under my observation. 
In placing before you some results at which I have 
arrived, I grant it would have been more satisfactory 
had I also been able to state somewhat of the history of 
each sample, giving, for example, its age, the conditions 
under which it had been kept, etc.; but I am unable to 
do so, and it probably will matter the less, seeing some 
of the results arrived at are quite independent of any 
such influences. I may state here that so much was I 
struck with the results which are shown in the accom¬ 
panying table, that in case of any mistake in the results 
obtained, I in each case, with a single exception, sent a 
duplicate sample to a practical chemist, to whom I am 
much indebted for his kindness, not only on this occa¬ 
sion, but also on many others, for entering with me into 
this inquiry, and other ways rendering me much help. I 
may also state that I sent him samples of most of the 
acids as well. In testing the irons he used the perman¬ 
ganate test, I adhering to the Pharmacopoeia bichro¬ 
mate as being less liable to error in the hands of a non¬ 
adept, but the results under both systems were substan¬ 
tially the same, in no case varying 1 per cent., and in 
most cases varying only a mere fraction. The table 
comprises seven different samples, the eighth being a 
special one, to which I will afterwards make reference. 
Saccharated Carbonate of Iron. 
1000 divisions bichromate solution = 14*75 grs. bichro¬ 
mate = 16*8 grs. iron from proto- to persalt. 
Fei C 0 3 
Fe,0, Total Fe. 
Standard 
37' per cent. 
6* per cent. = 
21*9 
Sample 1 
26*27 
11*8 = 
20*81 
2 
33*02 
4*54 = 
19*11 
3 
24*75 
11*03 = 
19*66 
4 
21*32 
15*77 = 
21*33 
5 
28*29 
9*21 = 
20*10 
6 
32*56 
5*29 = 
19*41 
7 
22*2 
6*36 = 
15*16 
8 
46*0 
a trace = 
22* 
Looking, in the first place, at the amount of carbo¬ 
nate only in each sample, the result is somewhat stag¬ 
gering and most unsatisfactory. Samples 4 and 7 con¬ 
tain fully a third less than the standard amount of car¬ 
bonate, 1 and 3 more than a fourth less, and 5 just over 
the fourth. It was this which led me in each case to 
estimate the amount also of peroxide present, so that 
some idea might be formed as to where the evil was, 
whether in the formation of peroxide from carelessness 
in making the carbonate, or in the actual absence of the 
iron itself. 
This last I was at first inclined to suppose would be 
the case, as it might not unreasonably have been sup¬ 
posed where results so far from the mark existed, some 
explanation might have been given either as to the ab¬ 
straction of some of the precipitate by the siphon during 
the process of washing, or, what was equally likely, the 
addition of an excess of sugar, and thus the loss of car¬ 
bonate not altogether imputed to the formation of per¬ 
oxide. The estimation of the peroxide, however, showed 
this was only partially correct, in so far as it brought 
out with a single exception, a moderately close approxi¬ 
mation to the standard percentage of pure iron , as is also 
shown from the accompanying table. We are therefore 
shut up, I think, to one of two conclusions from the 
results arrived at in connection with these samples, viz. 
first, that the protosalt had already been converted into 
a persalt previous to the formation of the carbonate, 
which might not unlikely have been the case were the 
commercial sulphate of iron used ; or second, and what 
I think the more probable conjecture of the two, that 
there had been great carelessness in allowing the iron to 
get oxidized during the formation and washing of the 
carbonate. We cannot imagine that by a peculiar co¬ 
incidence all the samples were aged, no more than it is 
legitimate to say that they were all recently made, 
although I have good reason for supposing that some of 
them were, and that none were exceedingly old. But 
indeed I am inclined to think the fault is entirely, or 
nearly so, confined to one of the two first conclusions 
above mentioned, or probably to both combined, as from 
experiments I have made I have found that any oxida¬ 
tion after the conclusion of the process or in the storing 
of the carbonate, even under the most favourable cir¬ 
cumstances for the formation of the peroxide, is very 
inconsiderable, if, indeed, there be any at all. For the 
purpose of trying this, and also for the purpose of trying 
the Pharmacopoeia process experimentally for the making 
of it, I shortly after beginning with some of these ex¬ 
periments, made a sample myself, the result of which is 
shown in sample 8 of the table above. I was exceedingly 
careful in the weighing, mixing, washing, etc. and for 
the iron I took the quantity required from one of the 
purest specimens of sulphate I think I ever saw. The 
result as will be seen was in every way satisfactory. 
There was only a mere trace of the peroxide on testing, 
and the carbonate stood about a half per cent, more than 
the actual possible strength by the Pharmacopoeia pro¬ 
cess, granting that there was no oxidation at all in the 
making. 
I need not enter into conjectures as to how this might 
have taken place, although I think the explanation easy 
enough. A small quantity only of the carbonate was 
made, and a very little less or more of any of the ingre¬ 
dients would account for the fact, but what I want to 
note is, that this sample has been exposed for the purpose 
of allowing the formation of peroxide, but as yet it is 
not present to any appreciable extent; and this sample, 
it must be remembered, was in every way a favourable 
sample for its formation, seeing it contained, so to speak, 
an excess of carbonate. I have, therefore, come to the 
conclusion that the sesquioxide is formed only in very 
minute quantity after storing, and more especially if any 
care at all is displayed in the mode of storing; and that 
in every case where the higher oxide is present in any 
quantity, as it is in most of the above samples, it has 
been formed during the process, or it has previously ex¬ 
isted in the protosalt. I may state here that I have in¬ 
variably used the zinc in preference to the protochloride 
of tin, as being the simpler process of the two, and also 
the least susceptible to error. 
In placing before you the foregoing results, it may be 
said that I have fixed on unfortunate samples on which 
to experiment, in so far at least as two of the substances 
are concerned, seeing the one is so apt to change in 
strength (acid), and the other so difficult to make of the 
proper standard strength (iron) ; but this, I apprehend, 
is one of the greatest arguments we could get in favour 
of this system of testing being adopted by each of us. 
We have the means, or can have them always at com¬ 
mand, for applying them; they occupy but little time in 
application, and are thoroughly simple, and the spirit 
and meaning of my paper will only be half understood, 
if I have failed to show that an examination from time 
to time of substances we may have in stock is as necessary 
as an examination of what we daily take into stock. 
