gSo Scientific NewSy Accounts of Books, ^c. 



Herfchel, L. L. D. F. R. S. (fee p. 360 of this number). 16. Chemical expenments on 

 zoophytes; with fome obfcrvations on the component parts of membrane, by Charles 

 Hatchett, Efq. F. R. S. 17. On the eledlricity excited by the mere contraft of con- 

 ducing fubftauces of different kinds. In a letter from Mr. Alexandar Volta, F. R. S. 

 profefTor of natural philofophy in the univerfity of Pavia, to the Right Hon. Sir jofeph 

 Banks, Bart. K. B. F. R. S. (abridged in this Journal, IV. p. 179.) 



Pojfil Wood, found at a very great Elevation. 



Citizen Villars has communicated a Memoir to the national inftitute of France, in which 

 he relates his having feen, in the department of Jfere, foITil wood, bedded in turf, at the 

 height of 2320 metres above the (a£lual level of the fea, and 850 metres 



above the moft elevated fituation, where wood grows, at prefent. The moun- 

 tain where he has made this iuterefting obfervation, is that of Lans, in the canton of 

 Aifans. The trees which are found are The roots, and parts 



of the trunk are obfervable. The latter of thefe ttees no longer grows in the vicinity. 



The author attributes the refrigeration which thefe mountains have experienced to two 

 leading caufes ; the firft is the excavation of the valleys, which has changed the elevation 

 of the fummits relative to their bafe, and the furrounding country ; and the fecond is the 

 deflru£tion of the ancient forefls, which extended contiguoufly upwards to great heights, 

 but cannot again grow at fimilar elevations, when once deflroyed, and the trees thus 

 deprived of their mutual flielter and defence. Soc. Fhilom. No. 33. 



ExtraB of a Letter from Mr. Humphry Davy, dated Ociober 2'^. fupplementary to his Paper 



on Galvaniftn, in the prefent Number. 



When I exhibited to Dr. Beddoes the phasnomenon of the renovation of the powers of 

 the galvanic pile, after it had ceafed to aft in hydrogen, nitrogen, &c. by momentary 

 immerfion in water, holding in folution atmofpheric air, he requefted me to try whether 

 oxigenated muriatic acid gas, folution of nitre, &c. would not increafe the effefts. The 

 fear of deftroying the filver prevented me at the time from trying the experiment on 

 oxigenated muriatic acid gas. I have fince, however, in endeavouring to afcertain whether 

 the eleftrical phsenomena of galvanifm were producible when the plates of the pile were 

 oxidating, (feparated from each other by a non-conduflor, and in contaft with an aeriform 

 flttid only) had an opportunity of obferving the very great power of this fubftance in pro- 

 ducing the galvanic decompofition of water. 



Ten pairs of plates of filver and zinc were connecled by cement, fo as to prevent the 

 alternate contaft of the metal. The fpaces filled by doths in the common pile, were 

 4 ufFered . 



