EDITORIAL. 
255 
article. Several formulae have been published, but perhaps none 
better than the following of M. Rabourdin, of Paris, viz.: 
R. Carbonate of magnesia, . - - 292 grains. 
Citric acid (crystals,) - - - 446 
"Water, 10 fluid ounces. 
Lemon syrup, - 2 " " 
Dissolve 138 grains of the carbonate in two fluid ounces of waler^ 
holding in solution 170 grains of citric acid, and pour it into a twelve 
ounce mineral water bottle. The remaining 154 grains is then tritu- 
rated with the remainder of the water, and also poured in the bottle. 
185 grains of citric acid is now added, and the bottle immediately and 
strongly corked and tied over. The citric acid reacts with a portion of 
the carbonate and forms citrate of magnesia, whilst the other part is 
converted into bicarbonate of magnesia by the liberated and compressed 
carbonic acid. As soon as, with occasional agitation, the opaque fluid 
becomes but slightly milky, the cork is carefully removed, the solution 
filtered, and reintroduced into the bottle, along with two fluid ounces 
of lemon syrup, and 91 grains of citric acid; when the cork is securely 
replaced and wired. 
These quantities produce twelve fluid ounces of the solution, each 
ounce containing about a dram of the citrate. The first solution may 
readily be made in larger quantity at once, and after filtering, be 
divided in the bottles, and the syrup and last portion of acid added to 
each before corking. If the carbonate of magnesia and citric acid are 
free from impurities, there is really no use in filtering after the second 
addition of acid, as the solution becomes clear a few hours after the 
last portion of acid has been added. We have tried this formula 
several times, and believe it worthy of adoption. The botfles should 
be strong, especially for the first addition of citric acid, and the cork 
should not be removed previous to fiUration, till the carbonate has 
nearly all been dissolved. 
The dose is from a half to a whole botfle. 
As several inquiries have been made relative to a formula for 
" Fluid Extract of Vanilla," the following is offered as affording a good 
article, viz.: 
Take of Vanilla, - - - - Sj- 
Sugar, - - - - gij. 
Simple syrup, - - - Oss. 
Water, ... - Oss. 
Deodorized alcohol, - f.^j. 
Cut the vanilla in thin transverse slices, triturate it with the sugar till 
