237 
Piper ovatum.—At the request of Kew the leaves and other parts of 
this plant have recently been the subject of investigation at the Research 
Laboratory of the egee Society by Pr ofessor W. R. Dunstan, 
4, and Mr. Henry Gar he material was received from 
Mr. J. H. Hart, F.L.S., Sapertntandlant of the Royal Botanie Gardens, 
Trinidad. ` 
Piper ee Vahl. (Ottonia Vahlii, Ath.) is a herbaceous shrub 
about 2-4 feet high with large papery leaves. It is found rather 
abundantly in woods in the central parts of Trinidad - is employed 
locally as a remedy for snake bite and hydrophobia. When chewed it 
gives rise to a persistent ee nica of the tongue and lips which is 
followed by a sensation of numbness accompanied by profuse salivation ; 
in these respects Fadblir pellitory. All parts of the plant, leaves 
stem and root, possess this meyi but the leaves and root appear to 
act more powerfully than the stem; the leaves haye an aromatic taste 
The following results are taken from a paper contributed by the 
ASe eee to the Transactions of the Chemical Society, 1895, 
A small quantity of an almost colourless, volatile, aromatic 
oil was obtained by distillation from the leaves. This was optically 
inactive, since a 6 per cent. solution in alcohol produced no rotation of 
the polarised ray. Without analysis the volatile oil of Piper ovatum 
was regarded as a sesquiterpene. Of the non-volatile constituents the 
active principle, called Piperovatine, forms datio P needles, 
which often crystallise in rosettes. In appea thes mew hat 
resemble the alkaloid caffeine. In strong Mioihel: the highly purified 
substance has the curious property of apparently gelatinising. zoe 
water is added to it in just sufficient kem] to cause precipitation. 
Further investigations will pro bably show that the constitution of 
iperovatine is precisely similar to that of such alkaloids as piperine, 
atropine, and aconitine. As regards its physiological action accordin 
power, the temporary character of its action, and, above all, its property 
of causing salivation, have interfered with its successful employment in 
the minor operations of dentistry. The solution of piperovatine in 
almond oil has, however, given promising results in affording temporary 
relief in painful superficial lesions.” It is added that there is a stron: 
resemblance between the physiological action of piperovatine and that o 
the root of pellitory. 
Preservation of Books in the m :—In the Kew Bulletin, a 
pp. 217, 218, an extract was given from — Museum Notes, Vol. 
No. 3, on the st means for preserving books from the ravages of idiot 
in the tropics. On this subject the TAS ‘letter been received 
a George Bidie ep E., formerly in charge of the 
Berry View, Paignton, South Devon, 
Sir, 19th March 1895. 
N the Kew Bulletin For 1894, p. 217, there is a memorandum 
on the “ Preservation of Books in the Tropics,” and I now write to 
