III. COMMENTS ON OFFICIAL ARTICLES. 
ACACIA. 
Smith, B. Grieg, discusses the bacterial origin of vegetable gums 
and describes the isolation of the several bacteria of the acacia type. 
He concludes that the natural gums are of bacterial origin and not 
due to the activity of higher plants, and that the differences in the 
several gums are due to the differences in the bacteria producing 
them. — Pharm. Prax., 1906, v. 5, pp. 113-114. (Evidently an ab- 
stract from J. Soc. Chem. Ind.) 
The Ph. Brit. Committee of Beference in Pharmacy asserts that 
AlcoclTs suggestion to limit the insoluble matter in acacia to 0.2 per 
cent is not supported, as a small proportion of insoluble matter might 
disqualify a very good gum. — Chem. & Drug., Bond., 1906, v. 69, 
p. 862. 
Philipp Boder, Wien, reports on 5 samples of acacia which were 
found to vary from 2.69 to 3.08 per cent of ash. The maximum ash 
content permitted b}^ the Ph. Austr. VIII is 3 per cent, which Boder 
believes too low as only 2 of the 3 samples enumerated above came 
fully within the prescribed limits. — Pharm. Post., Wien, 1906, v. 39, 
p. 264. 
G. Hell & Co., in Troppau, found the ash of commercial samples 
of acacia to vary from 2.25 to 3.35 per cent while the acid number 
varied from 10.08 to 18.20. — Ibid., v. 39, p. 181. 
Dieterich, Karl, reports on 5 samples of acacia. The ash content 
varied from 2.85 to 3.20 per cent and the acid number from 12.56 to 
15.12. — Helfenberger Annalen 1905, 1906, v. 18, p. 83. 
Ohliger, Willard, reports acacia containing pieces of bark from the 
tree. — Proc. Michigan Pharm. Ass., 1906, p. 46. 
The editor of Notes & Queries explains the absence of reaction 
between bichloride of mercury and the new mucilage of acacia as 
follows : 
It frequently happens that a viscid body like mucilage or syrup will prevent 
the precipitation of metallic salts. This is due in part to the viscid character 
of the vehicle, but it is also thought that a salt is formed— in this case mercury 
arabinate — which remains in solution. Such salts of feebly acting radicals are 
soluble in alkaline solutions, but may be precipitated in neutral solutions. The 
salt in this case is similar to the albuminates, which are soluble in an excess 
of albumin and alkali, but are decomposed by acids. — Drug. Cir. & Chem. Gaz., 
N. Y., 1906, v. 50. p. 93. 
11667— Bull. 5S— 09 8 
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