-2J>? Experiments and Inferences refpeffing 



T. 



^j^ccount -cf cerium Experiments and Inferences reJfenlng.theCpmhuJllon of the .Diamond^ ant 

 the Nature if its Compqfitm, By C.iT.JZ£y Gurwo.N.* 



J- HAT >the diamond is a.£ombullible !body was long ago conjeftured by Newton, froin 

 •its ftrong.attrafUon to theraysof light, and this truth has fince been verified by many experl- 

 Ljnents. With regard to the nature of this gem, the firft experiments of Guyton, publiOiedip 

 ^785 f, onits totalcombuftion in fufed nitre, feemedto {hew that itjv>s fimilar tocharcoal, be- 

 jcaufe itieft an efFervefcent alkali j tbi« fufpicion.was rendered ftill more probable by the exa- 

 jnination by Lavoiilerof the^as.remainin^ after burning it in clofe velTels, which.proved t9 

 ^e carbonic ; and very lately Mr. Tennant has given a new verification of this important faft, 

 i;4)y.rej)eating the combudion of the diamond in a. crucible of ^old, as Guyton had pointefl 

 jMt in order to oblain.a refiduc perfcdlly exempt.from foreign matterj;. 



There were neverthelefs many reafons for doubting the perfefSl ideiitity of .the diamond 



,cand.carboue- Independent of the extrenje difference «f their external chara£lers, the author 



•aof the prefent communication ^ftatcd .fcveral fadls to the inftitutc, which fhew that. the chei- 



>;OTical habitudes of the two bodies are not confiftent with this ideptity. Fpr if, the diamond 



twere pure carbone, why does it not detonate with the oxygenated muriate of potafh, and dif- 



oxygenate fulphur, arfeiiic^.phofphoruSj.^nd fuch metals , as are. fufRciently fixed to determinjc 



its combination with. ox^geji ? Why does. it.not form, carburets? orcondud theeledrjc fluid? 



Jt is known that the power of aggregation fometimes counterbalances the power of chemical 



afEnity; but this does not happen when the bodies are fufficiently fixed, and the temperature 



ifufiicrenily elevated to give efFedt to the weakeft attradlions of compofition. 



It remained, therefore,, that fome di/coveries fhojuld be raade to reconcile ai^d explain fa^ 



.apparently fo difcordant.§. Our author judged that the, explar;atiora .was to be fpught by .a 



<3iligent refearch into the phenomenon of the combuftion of this fubflance, and he hopes that 



ithe narrative of his experiments made at the Polytechnic fchool, in conjunction with the citL- 



,\zens Clouetand Hatchctte, .in the fifth and. fixth, republican years, \f\\\ (hew that his expec- 



>:lations were not fll founded. 



The firft experiment: was made on the 9th Fruflidor, in the year 5 (Augufl: 26, I792J. 

 _An inverted velTcl of white. glafSj 18,3 centimetres ia diameter, and 5580 cubit centimetres^ 

 .{A. fig. I. jjlate 14.) in capacity, was placed on the fhelf of a trough containing mercury. 

 : Near, this trough was fixed an air-pump ^» to extract the common air by meaos of a re- 



* 

 >• Abridged! from the comtnuriication re?d at the fming of the firft, clafs o£ the French National, l.nftit.utff 



a*6 Prairial, in the year 7 (June 14, 1799); infcrted in the Annalts de Chimie, XXXI. 7?. 



• f French edition of Bergmanh's Treatifes, vol. XII. p.U4. 

 J Philof. Tranf. 1797 ; or this Jotirnal, I. 177, 199. 



'•§ -Cit. Btrthollet, in his Lcfiures at the Norirjl School, confldcrs it ftill as a matter' Of doubt Wbethertiie 

 «''^inQn4 be cryflallized .carbone, or that principle combined with fome other matter. 



