GRANULAR CITRATE OF MAGNESIA. 
195 
I now pass on to the composition of the granular citrate of magnesia, which, 
as Mr. Draper says, consists of— 
Sulphuric, A 
Soda and Tartaric, / • . 
Magnesia. and f Aoid9 ’ 
Carbonic J 
and, I may add, sugar and citric acid, and, as a flavouring, essence of lemon. 
The article analysed by Mr. Draper contained no citric acid : to use his 
own words, li the absence of citric acid . . . was also established.” I have 
made several attempts myself to obtain a granular preparation without any, 
and I know others who have done the same ; but have never succeeded. 
All the samples which I have examined contain it, and I think we may there¬ 
fore conclude that citric acid is now always a constituent. That sugar enters 
into it is proved by the taste, although I know of one firm who for some 
years used the following formula :—■ 
Sodae Bicarb.16 oz. 
Acid. Tartaric. . . . 10^ oz. 
Acid. Citric.5 oz. 
Magnes. Sulph. ... 1 oz. 
with a little water to help the granulation. Any one tasting this would at 
once be struck with the difference between it and that now generally sold. 
The proportion generally varies from 6 oz. to 16 oz. of sugar to 16 oz. of soda, 
but in one or two cases I have found it to exceed that. 
As we are all aware, the trade in this article has increased enormously 
during the last few years, and at the same time the price has been reduced ; 
the manufacturer therefore has had to turn his attention to the use of the 
cheapest materials. 
The articles above enumerated are still all that are to be found in it, but 
they do not convey the information as to how they exist. It is at once evi¬ 
dent that the maker must keep down the proportion of citric acid, and add as 
much sugar as possible, for while nothing, so far as my experience goes, will 
make a better preparation than equal parts of citric and tartaric acids, yet, 
when cost has to be considered,* * it is very evident that the more expensive 
one must be replaced by something else. 
Now, sugar, to a certain extent, promotes granulation, but it will not do 
alone. Water drives out too much gas, but in the use of a small proportion 
of sulphuric acid, or bisulphate of soda, the manufacturer can reduce bis cost 
to a minimum. I believe the first mention of the use of bisulphate of soda is 
to be found in the ‘ Chemical News,’ vol. xvi. p. 269, by a Mr. Scott; but, 
from the way it is mentioned, the wn-iter did not, apparently, know much about 
it from experience. I do not remember to have seen the use of sulphuric acid 
recorded anywhere, though it has had a limited use, to my knowledge, for three 
years. I have not, however, found the employment of these articles so gene¬ 
ral as might be expected among the cheaper preparations, notwithstanding 
the publicity given to the suggestion. The use of citric acid alone makes the 
article so much more difficult to manufacture, and not so good for keeping or 
effervescence, that I believe none is now made ; though, for a while, a house 
made and sold a ton or two of it. It is rather softer on the palate than when 
containing tartaric acid. 
In concluding this part of my paper, I would recommend any one who 
wishes to imitate the articles now sold to try the following formulae :— 
Sodae Bicarb. . . 16 oz. 16 oz. * 
Acid. Tartaric. . . 8 oz. 10 | oz. _ 
* This applies particularly at the present time, August, 1868, when tartaric is worth Is. 'id. 
and citric 2s. 8 d. per pound. 
