180 
VARIETIES. 
One very spongy piece had a sp. gr. of only 0.511. In general, there- 
fore, English rhubarb has a less sp. gr. than the Russian. The greater sp. 
gr. of the latter sort depends upon the larger proportion of oxalate of lime 
which it contains. The following table represents the results of the author's 
of the two sorts 
Russian Rhubarb. 
English Rhubarb. 
Sp.gr. . . . 
0.918 
0.857 0.743 
0.826 0.739 0.617 
Rhein . . . 
4.3 
3.8 3.2 
5.3 4.9 3.1 
Resin . . . 
10.3 
8.5 8.1 
4.7 5 8 4.6 
Oxalate of lime . 
15.2 
11.7 11.4 
10.3 8.7 3.1 
Extractive . . 
14.7 
13.5 22.6 
32.3 39.5 26.9 
Woody fibre . 
14.0 
16.4 21.9 
23.8 31.2 43.3 
In English rhubarb the proportion of resin is smallest, of extractive the 
largest. In the Russian sort the proportion of oxalate of lime is considera- 
bly greater. In the English sort the rhein and woody fibre preponderate. 
According to the author, the purgative quality of rhubarb depends on the 
resin and oxalate of lime, and the tonic properties on the rhein and extractive 
matter ; hence Russian rhubarb is more purgative than the English, while 
the English is more tonic than the Russian — Pharm. Jour, and Trans. July 
1, 1850, from Arch. d. Pharm. 2 R., bd. cix., s. 165—167. 
Neutral Citrate of Soda, a new Purgative suitable as a substitute for Saline 
Mineral Waters, fJie Citrate of Magnesia, Sulphate of Soda, of Potash, of 
Magnesia, &c. — M. Gujchon, a pharmaceutist of Lyons, has suggested the 
use of the neutral citrate of soda as a substitute for the citrate of magnesia 
and as being but half as costly. 
This salt is white, without odor, often very slightly acid ; it effloresces 
slightly on exposure to the air; it crystallizes in six-sided pyramids; its 
chemical formula is NaO, C 4 H 4 QJ — [More probable, 2 NaO, HO,-f C^HsO^, 
-{-HO? The formula stated in the text is evidently incorrect. — Ed. Am. 
Journ. Pharm.] 
Acid . . .... .49 
Oxide of sodium .... .26 
Water tyv*** . . . . 25 
100 
It is easily preserved • an excess of acid diminishes very decidedly its pur- 
gative powers. Dr. Patton, chief physician to the hospital of Antiquaille of 
Lyons, has experimented with it both in the state of a neutral salt simply 
dissolved in water, or in a demulcent drink, and in the stale of a neutral 
salt very slightly acidulated and sweetened. Young subjects are purged by 
it in the dose of 40 grammes, and adults in the dose of 55 grammes, 
These experiments, which have been repeated by many physicians of 
