^34 Analyjii of Bone, &c,'^EIaJlic Gum. 



can no more be regarded as bone, than cliarcoal can be confidered as the vegetable, of 

 which it retains the figure and fibrous flrufture. 



Bones which keep their figure after combuftion, refemble charcoal made from vege- 

 tables, replete with fibre ; and cartilaginous bones which lofe their fhape by the fame 

 caufe, may be compared to fucculent plants, which are reduced in bulk and ftiape in a 

 fimilar manner. 



From thefe laft experiments, I much queftion if bodies, confifting of phofphate of lime 

 like bones, have concurred materially to form ftrata of limcftone or chalk ; for it appears 

 to be improbable, that phofphate is converted into carbonate of lime, after thefe bodies 

 have become extraneous folllls. 



The deftrudlion or decompofitlon of the cartilaginous parts of teeth and bones in a foffil 

 ftate, mufl have been the work of a very long period of time, unlefs accelerated by the 

 a£tion of fome mineral principle ; for after having in the ufual manner fteeped in muriatic 

 acid the os humeri of a man brought from Hythe in Kent, and faid to have been taken 

 from a Saxon tomb, I found the remaining cartilage nearly as compleat as that of a re- 

 cent bone. The difficult deftrudlibility of fubftances of a fomewhat fimilar nature, 

 appears alfo from the piercing implements formed of horn, which are not unfrequently 

 found in excavations of high antiquity. 



III. 



Some Account of the Elajlic Gum Vine of Prince of Wales's IJland, and of Experiments made 

 on the milky Juice which it produces: with Hints refpeSing the ufeful Purpofes to which it 

 maybe applied. By James Howison, Efq.* 



Vy UR firft knowledge of the plant being a native of our ijland arofe from the following 

 accident. In ourexcurfions into the forefts, it was found neceflary to carry cutlafles, for 

 the purpofe of clearing our way through the underwood. In one of thofe an elaftic gum 

 vine had been divided, the milk of which drying upon the blade, we were much furprized 

 in finding it pofiefs all the properties of the American Caout-chouc. The vine which pro- 

 duces this milk is generally about the thicknefs of the arm, and almoft round, with a 

 ftrong alh -coloured bark, much cracked, and divided longitudinally ; has joints at a fmall 

 diftance from each other, which often fend out roots, but feldom branches; runs upon the 

 ground to a great length ; at lafl: rifes upon the higheft trees into the open air. It is found 

 in the greateft plenty at the foot of the mountains. Upon a red clay mixed with fand, in 

 fituations completely ftiadcd, and where the mercury in the thermometer will feldom ex- 

 ceed fummer heat. 



• Afutlc Refearches, V, 157. 



In 



