1150
ELEMENTS OF MATERIA MEDICA.
Prout {Phil. Trans, for 1827), Guerin ( Journ. de Chim. Med. vii-and Mulder (Pharm. Ce.ntral-Blatt Jiir 1839, S. 137).
742 )'
Gum Arabic.
BERZELIUS PROUT MULDER
Total. 100000
41-46-552 100
1000
45106-1048-800 0
100 00
Soluble f lGumBa^ouERe^___
43-K 5
6-26
50-28
o-o
100-00
of
According^to o )fc
Mulder gives, as the formula for gum Arabic, C 12 H 10 O 10 .the first formula the atomic weight will be = 186; accordingsecond, = 162. 0
The proximate analysis of gum lias been made by Guerin ( op • sU "cit.)
Gum Arabic. Gum Senegal. Gum Bassord.
Soluble gum {Arabia) . 79-40 . 8110 . 11 20
Insoluble gum ( Bassorin ) 0'00 . 0 00 . 6131
Water . 17-60 . 1610 . 21-89
Ashes . 3-00 . 2 80 . *5-60
Total. 100 00 . 100 00 . 100 00
llizabl c
1. Soluble Gum or Arabia. —Is a colourless, inodorous, insipid, uncryst® 1 * jtsolid, soluble in both hot and cold water, but insoluble in alcobol, ether, and oil®- ^combines with alkalies. Sulphuric acid converts it into a saccharine substance- •„parts of arabin treated with 400 parts of nitric acid, yielded Guerin 16 88 of ^acid, with a little oxalic acid. From cerasin, orprunin (p. 1127), it is distinguish ' A.
I TL» -1__*_I__L‘ L ’ J?_.*_L-J IT y i
49 85, ad nitrogen 0-14. . j,ot
2. Insoluble Gum or Bassorin. —Is distinguished by its insolubility in water, b® rtsand cold. It absorbs in water, and swells up. It is insoluble in alcohol. h. j.treated by 1000 of nitric acid, furnished 22 61 of mucic acid, with a little oxan®
. " I 6 ' 85 ' ‘ish
It consists, according* to Guerin, of carbon 37*28, hydrogen 55*87, and oxygen ^
c. Salts. —The ashes of gums Arabic and Senegal consist of carbonates of P_.jj c3land lime, with minute portions of chloride of potassium, oxide of iron, alumina, 0 fand magnesia. The carbonate of lime is formed by the decomposition of the nI * p0 si-lime contained in the gum, while the carbonate of potash results from the deco rtion of acetate of potash. ^
Chemical Characteristics. —Gum Arabic is soluble in both hotcold water, forming mucilage. Alcohol precipitates the gumsolution. Diacetate of lead causes a white precipitate {gummate 0 // . gwith the solution. A solution of silicate of potash (prepared by lu athree parts of carbonate of potash with one part of silver sand) caU , ^white flaky precipitate. Oxalate of ammonia a white precipit 3 ^ ^ j slate of lime). When a concentrated solution of sesquichloride of 11 ;ldropped into strong mucilage, the whole becomes, after some ho ,^ ebrown semitransparent jelly. Nitrate of mercury produces a preci?with a solution of gum. , s 0 f
Physiological Effects, (a.) On animals generally .—The e "! e ^ 0 gs)injecting solutions of gum into the veins of animals (horses an