CONTRIBUTIONS TO BOTANY. 
Ill 
found to be identical. Tlie quantity existing in the Yerba de 
Paraguay has not been ascertained, but it is probably not less 
in amount than in coffee. Coffee, however, derives its pleasant 
flavour principally from its peculiar acid, called caffeic acid, 
which is very analogous to kinic acid, or the vegetable acid of 
Cinchona-barks. Dr. Stenhouse relates that when caffeic acid 
is treated with sulphuric acid and binoxide of manganese, it 
yields the peculiar principle called kinone, and that the Paraguay 
tea also furnishes kinone when subjected to a similar treatment. 
It is worthy of notice that the leaves of our common Holly, 
when exposed to the action of the same reagents, also yield 
kinone, as do the whole of the Cinchona tribe of plants and 
Asiatic Tea. There is another vegetable product of an analogous 
nature, the guar and, or inspissated juice of the Paullinia sorbilis, 
prepared by the Indians of Para, the infusion of which affords a 
very refreshing drink, of which the Indians are very fond. This 
has been analysed by Dr. Stenhouse, and found to contain a 
large proportion of theine. It is singular that Mau, in the 
lowest grades of cinlization, should have had the faculty of 
distinguishing and applying to his use those plants which con- 
tain the peculiar principle to which the tea of China owes its 
invigorating property. 
On Vtllaresia. 
This genus of the Flora Peruviana is but little known, only one 
species having been yet described. Poiret (in 1808) considered 
it to belong to Aurantiacea, — an idea derived, no doubt, from the 
vernaeular name of the typical species, “ Naranjillo.” Jussieu 
(in 1821) gave a very correct description of that species, accom- 
panied by analytical figures (Ann. Sc. Nat. xxv. tab. 3), and 
placed the genus rightly in Aquifoliacece. Don (in 1832) de- 
scribed the same plant under the name of Citronella mucronata, 
when he assigned it a position near Cassine. Hooker and Arnott 
(in 1834), in their enumeration of Chile plants (Hook. Journ. 
Bot. i. 283), arranged the genus next to Myrsine. Jussieu 
states that some botanists had considered it as belonging to 
Menispermacea •, and Dr. Bindley (in 1836) appears to have 
then adopted similar conclusions in referring it to Schizandracea; 
(Introd. Bot. 553), but afterwards (in 1846) he retracted this 
opinion (Veg. Kingd. 598), and, following the view of Jussieu, 
placed it in Aquifoliacece. Endlicher pursued the same aiTange- 
ment in his ‘ Gen. Plant.’ No. 5709. 
On a former occasion, I adduced abundant evidence to show 
that the Icacinacece do not belong to Olacacece, and that the 
