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usually obtained from 5 kilos of bark. The bark is now extracted hot, until 
exhausted, with 85 per cent alcohol, to which a little dilute sulphuric acid has 
been added. The alcohol is then distilled and to the aqueous, acid residue, which 
is usually of the consistency of molasses, double the volume of water is added. 
This solution is left standing in a cold place for a few days, after which it is 
centrifuged to separate as much of the gum as possible, for, in order to obtain a 
good yield of the dita alkaloids, it is necessary to get rid of the gummy substances 
in some way, as otherwise the alkaloids seem to be held in solution so that they 
can not be shaken out with immiscible solvents. 
The aqueous solution is now gently evaporated in vacuo to an appropriate 
volume, made alkaline with sodium carbonate and shaken out with ether as long as 
this solvent removes anything. Upon evaporation, a small amount of ditamine is 
obtained, usually 0.3 gram from 5 kilos of bark. The aqueous solution is now 
rendered very strongly alkaline with sodium hydrate and shaken out several times 
with chloroform; it is usually found necessary to centrifuge the emulsions obtained 
in this way. The chloroform is now distilled off and the residue is dissolved in 
hot, 1 per cent hydrochloric acid and the solution evaporated to a small volume. 
Concentrated hydrochlorie¢ acid, or a soluble chloride, is now added in considerable 
quantity, whereupon echitamine hydrochloride separates in needle-like crystals, 
which at this stage are usually somewhat brown. The hydrochloride of the 
alkaloid is now recrystallized from water, two recrystallizations usually being 
suflicient to render it pure, the yield from 5 kilos of bark being 5 to 7 grams. 
As it will be necessary to work up several hundred pounds of dita 
bark to obtain a sufficient quantity of alkaloid for a more extensive 
study, I have considered it necessary to develop a simpler and cheaper 
method of obtaining the alkaloid. ‘These experiments have occupied 
much time. It was soon shown that the alkaloid can be completely 
extracted with dilute acids, but precipitation of the solutions thus 
obtained, according to the methods of Mayer or of Kippenberg, or with 
phospho-molybdie acid, gave no satisfactory results, hence the following 
method was finally adopted : 
(b) The finely powdered bark is percolated in one-half per cent acetic acid 
until exhausted; this solution is then evaporated in vacuo to a small volume, 
preliminary experiments showing that such treatment does not cause any loss or 
decomposition of the alkaloid; this solution is then continuously boiled with a 
little animal charcoal to remove some of the gum and is then centrifuged. Care 
must be exercised because too much animal charcoal takes up alkaloid as well 
as gum. This process gives a fairly clean solution, which is made alkaline, shaken 
out with solvents, and treated further as in method (a). The yield is the same. 
The following tests on guinea pigs show that practically all the 
physiologically active constituents are obtained from the bark by this 
treatment. One kilo of bark, which had been found to contain 0,135 
per cent of alkaloid, was treated according to method (b) and the dilute 
acid solution evaporated in vacuo to 135 cubic centimeters. Five cubic 
centimeters of this crude solution were taken for physiological tests, 
and from the remaining 130 cubic centimeters, 1.3 grams of echitamine 
hydrochloride were obtained. The physiological tests resulted as follows: 
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