297 
Later, Dr. Bancroft says : " I have given Duboisia in asthma and photophobia. 
It causes much dilatation of the pupil, and indistinct vision, also confusion of intellect, 
particularly at night, a thirsty dryness of the throat, and loss of taste. At present no 
valuable results, except the mydriatic, are apparent." 
In a paper read by Dr. Bancroft before the Queensland Philosophical Society, 
10th October, 1878, entitled " Further remarks on the Pituri group of plants," are 
some further notes on Duboisia myoporoides, or " Duboisia." He describes the active 
principle as a yellow, oily-looking substance, which refuses to crystallise, either alone, 
or with the common acids. It mixes with water readily, and is not volatile at 212 deg. F. 
The leaves owe their active properties to the presence in them of an alkaloid 
called duboisine, which Ladenburg j renounces identical with hyoscamine; albeit 
there are minute differences between them. The method adopted by Mueller and 
Hummel to obtain the alkaloid, and a short account of the latest researches of Ladenburg 
in regard to its position, are given herewith. (See also Liversidge, Proc. Roy. Soc. 
N.S.W., 1880, 125.) 
" Duboisine is a volatile (non-volatile according to Bancroft J.H.M.) alkaloid 
of the leaves and twigs of Duboisia myoporoides R.Br., and probably identical with the 
piturine found by Staiger in D. Hopivoodii F.v.M. Prepared like nicotine, it is a 
yellowish, oily liquid, lighter than water, of a strong narcotic odour, resembling that of 
nicotine and also cantharides, of a very strong alkaline reaction; neutralises acids 
completely ; dissolves in any quantity of water, alcohol or ether ; throws down ferrous 
oxide from ferrous sulphate; dissolves in concentrated acids, forming a colourless 
solution. Its hydrochloride, in a weak aqueous solution, is precipitable by iodide of 
potassium, some double iodides, and by tannic acid, not by other alkaloid reagents. 
Nicotine, which duboisine resembles, is distinguished from the latter by its specific 
gravity, its less powerful odour, and by its hydrochloride in a diluted aqueous solution 
being precipitated by phosphomolybdate of soda, picric acid, and chloride of platinum." 
(Mueller and Hummel, in Wittstein's Organic Constituents of Plants.) 
In 1880, Professor Ladenburg (Comptes Rendus, xc, 874) during his investigation 
of the mydriatic alkaloids, arrived at the conclusion that duboisine, the base obtained 
from D. myoporoides, was identical with hyoscine* (Pharmaceutical Journal (3), xi, 351), 
though, as generally met with, probably contaminated with some impurity. This 
opinion was subsequently challenged by Herr Harnack, who affirmed that duboisine 
exercised a much stronger physiological action than hyoscine. Professor Ladenburg 
has, therefore, been induced to reinvestigate the subject, working upon a sample of 
duboisine supplied by Herr Merck. The base, as received, was a yellow-brown sirupy 
mass, which was dissolved in hydrochloric acid and precipitated with gold chloride. 
The gold salt had at first a resinous appearance, but after four recrystallisations it 
became homogeneous, melting constantly at 197 degrees to 198 degrees, and showing all 
* Hyoscyamine in the abstract, through inadvertence. 
