I J4 Mctlans produced by the Ematiatktis of OJorgut Bod'u3. 



bodies in its vicinity, and carries them again to the camphor by ftarts The author con- 

 cludes that an ebllic fluid efcapes from the odorant body in the manner of tJie fire of a 

 fufee, or the difchargc of fire-arms. * 



g. When there is a certain proportion between the lieight of the water and that of 

 the fmall fragment of camphor, the water is brilkly driven off, returns again, to the cam- 

 phor, and again retires, as if by an cxplofion, the recoil Of which often caufes the camphor 

 to make part of a revolution on its axis. 



8. Fragments of camphor of the fize of a pea, floated upon water in a difh of metallic 

 leaf four or live lines in diameter, communicated motion to thcfe di(hes, though Icfs 

 fwift than was exhibited by the camphor alone. If the glafs in which this experiment is 

 made be nearly filled with water, and covered by a (plain) glafs whioh intercepts the 

 contaift of the air, the motion decays and ceafes. 



9. Camphor alone moves more rapidly than when it is placed upon the metallic plate. 

 The author infers that the immediate contatl of the water favours the difengagement of 

 the fluid which produces the motion. 



10. Camphor evaporates thirty or forty times more fpeedily when placed upon water, 

 than when entirely furrounded with air. 



11. Camphor, during the ai£l; of dilFipation in the air, prefervcs its form and its opakc 

 whitenefs ; upon water it is rounded, and becomes tranfparent, as if it had undergone a 

 kind of fufion. It may be inferred that it arifes from the acquired motion, which caufes it 

 to prefent a greater furface to the air. 



12. In fa£\, out of 12 equal fmall pieces of camphor, fi-t being fufpended under a 

 glafs with quick-lime, and very dry, and fix others being fufpended in a moiftened glafs, 

 together with a wet fponge, the volatilization was alike in each -, and the water in this 

 cafe not touching the camphor did not appear to contribute to the efFeft. 



13. It is neceflary for this purpofe that the water (hould direflly touch the camphor. 

 Accordingly, fragments of camphor placed on blotting-paper continually wetted, are difll- 

 pated with the fame fpeed, and become equally tranfparent, as when a£lually placed on 

 water, though they exhibit no motion. 



14. When fmall pieces of camphor are plunged in water, the camphor becomes rounded 

 and tranfparent, does not acquire any motion, and its dilfipation is lefs perceptible than in 

 the air. The concurrence of air and water is therefore necefiary to difengagc the fluid 

 which is the caufe of the motion and total diflipation of odorant bodies. 



15. The motion of odorant bodies upon water decays and ccafes fpontaneoufly at the 

 end of a certain time; becaufe, the water having then contradled a flrong fmell, the 

 volatilization takes place in all the points of its furface ; and the fmall mafs being thus, fur- 

 rounded by the odorant fluid, which is no longer air, d'flblves, as in the ordinary odorant 

 fluids, without forming the gafeous jet which is the caufe of the motion. The author 

 compares the volatilization of the aromatic fubftance to a combuftion excited by water. 



In this place the author dwells for a Ihort time on the phenomena he had defcrihed. 

 He obferves that thefc eiTc£ls may be rendered palpable by touching the furface of the 

 water on which the odorant fubfl:ances move, with a pin dipped in oil. At the very inftant, 

 quick as Jightning, thcfe particles, as if ftruck, ceafe to move. A coloured pellicle, formed 

 by the oil, is fecn on the furface of the water. The water penetrates the pores of the oil, 



like 



