1816.] during the Year 1815. 49 
their solution occasioned the precipitation of lemon-yellow flocks. 
From these properties Pfaff considers the substances in question as a 
peculiar species of resin of cinchona. 
At the same time a set of experiments was made to determine 
whether infusion of nutgalls, tartar emetic, and gelatin were pre- 
cipitated by one and the same constituent in Peruvian bark, or by 
different constituents. The following were the results obtained. 
The substance which at once precipitates tartar emetic, infusion 
of nutgalls, and gelatin, is equally soluble in water and alcohol, 
and possesses the properties of those vegetable bodies which have 
received the name of saponaceous matters. 
The substance which precipitates infusion of nutgalls and 
tartar emetic appears to exist in all the varieties of cinchona; but 
to vary in its properties in the different species. 
The substance which precipitates the infusion of nutgalls is 
that in which the bitter taste of the Peruvian bark resides ; yet its 
combination with infusion of nutgalls has no bitter taste. 
The substance which precipitates gelatin differs entirely from the 
Jast mentioned constituent. It belongs to that modification of 
tannin which precipitates iron of a green colour. 
5. Pollen of Tulips.—Professor John, who is one of the most 
active and laborious chemists in Germany, and has already pub- 
lished a number of volumes of analyses, chiefly of vegetable and 
animal substances, has, among other things, turned his attention to 
the pollen of vegetables. The pollen, he finds, always contains a 
peculiar substance, which has hitherto been considered as allwmen ; 
but to which he has given the name of pollenin. ‘This substance 
forms with nitric acid a bitter tasted matter. It is insoluble in alco- 
hol, ether, water, oil of turpentine, naphtha, carbonated and caustic 
alkalies; and when distilled yields ammonia and an acid liquid. 
The pollenin of different plants varies somewhat in its properties. 
John has also found that wax, whether extracted from vegetables 
or bees’-wax, consists of two constituents: the first of which, 
which is soluble in alcohol, he calls cerin; the second, which is 
insoluble in that liquid, he calls myricin. The following is his 
analysis of the pollen of tulips. 
He digested the pollen in a sufficient quantity of alcohol to take 
up every thing soluble. There remained a bluish-green powder. 
This was pollenin, coloured by a blue pigment which exists in 
this pollen; for the natural colour of pollenin is yellow. 
The alcohol solution, when filtered, bad a violet-blue colour, 
and gradually let fall a precipitate, which was cerin. The liquid 
freed from cerin, being evaporated, let fall a violet-blue extractive 
matter, which was soluble both in water and alcohol. The aqueous 
solution of this substance possessed the following properties. 
It precipitated sugar of Jead emerald green. 
lime water, ditto, 
muriate of barytes, no change. 
nitrate of mercury, violet blue. 
Vor, VIL N° J. Db 
