Marabelli on Preparation of Extracts by Storck’s Method. 47 
he wished always to prepare extracts with the unpurified juice of 
these plants, that is, with juices evaporated to the due consistence 
without separating from them the fecu/a: this practice has been 
generally adopted even by other physicians. 
But, on attentively observing the extracts obtained by this pro- 
cess, it was discovered that the fecu/a existing in them undergoes 
a greater or less degree of carbonization during their prepara- 
tion; and hence the extracts themselves experience a marked 
alteration. It was imagined to avoid this inconvenience by pro- 
ceeding in the preparation of this kind of extracts in the following 
manner, which consists in exposing the juice of the vegetable from 
which it was designed to make an extract, to a gentle heat, in 
collecting a part of the fecuda which is separated from the juice 
by means of the heat, in evaporating the juice purified in this 
manner to the consistence almost of an extract; and finally, at 
the end of the operation incorporating with it the fecula placed 
apart. In a similar manner the abovementioned extracts have 
been prepared by Parmentier, one of the more recent writers who 
has diffused much light on the nature and preparation of the ex- 
tracts ; and this method has been followed in preference to that 
of Storck by the best informed French and Italian therapeutists. 
But this process runs the risk, that sometimes the first fecula 
which can combine with the extract may suffer some alteration, 
and this in consequence of the length of time necessary to re- 
duce the purified juice to a due consistence, especially where the 
quantity is considerable, In other respects, it is unquestionable 
that by this process we may succeed in incorporating the extracts 
with this fecula in its uatural state, and consequently obtain 
these extracts exempt from carbonization. But, opposed to this 
advantage, the extracts prepared according to this process are 
subject to another imperfection, since, in consequence of the fe- 
cula which is found in a grumous state, it cannot be incorporated 
either intimately or equally throughout the mass: the extracts 
thus obtained contain more or less of small clots of a different 
colour: besides, it is difficult to reduce them to a convenient de- 
gree of consistence without danger of altering them, consequently 
they are subject to become rapidly mouldy. 
In the Apparatus medicaminum which | was commissioned to 
compile for the use of our hospital in 1790, and also in another 
which I published in Brescia in 1797, I have detailed a process 
for preparing extracts of the above kind, by which means they 
are obtained with all the necessary requisites for keeping, and in 
a state more fit for medical use. The process consists in sepa- 
rating the fecula by the ordinary method from the juice which 
is to yield the extract. Dry this fecula carefully either in the 
sun, or with a moderate heat ; then pulverize it into a fine sie 
er, 
