Anal^ts t)f the ChrjfJltt. ' , xxe 



»Hd Wallerlus has plactd it between the emerald and the garnet. The account of this 

 author is copied in the note below*. " 



Kirwan ufes the term chryfolite to denote merely the peridot, which neverthelefs 

 differs from it greatly in' the nature of its principles- 



Achard of Berlin analyfed a fpecies of chryfolite in which he affirms that he found 

 Clex 0.15 i alumine 0.64 ; lime 0.17 ; iron o.i. 



But the refults of this analyfis are fo diiFerent from mine, that I ftrongly fufpe(3t he muft 

 have operated on a different ftone from the true chryfolite. This fufpicion is fo much 

 the more probable, as the name of chryfolite has been given to many different ftones, 

 particularly the peridot, the chryfo-beryl, the olivine, and in general all ftones which 

 have a greenlfli yellov/ colour. 



Citizen Launoy, in a journey he is at prefent performing.in Spain to colle£t the objeils 

 of natural hiftory, found in the hands of a dealer a confiderable quantity of chryfolitcs, 

 which he fent to Paris ; and the Council of Mines having purchafed part of them, dire£led 

 nje to fubmit them to analyfis. 



It was not long before I difcovered that this fofTil, which has all the external appearances 

 of a ftone, is not truly of that clafs ; but that, on the contrary, It is a fait compofed of an 

 «cid and a bafe. which are both well known; namely, the phofphoric acid and lime. 



As foon as I had obtained this firft refult I enquired of Citizen Hauy, whether he had 

 compared the maffes of chryfolite with thofe of the apatite or cryftallifed phofphate of 

 Kme. He anfwered, that he had not, but that he had among his papers the relative refults o£ 

 the primitive forms of both, and would immediately compare them. He found with 

 pleafure that they did not differ in the leaft appreciable quantity ; and this conclufion may 

 even be drawn. from the refults of which he has given an abftradt in his treatife publiflied ia 

 the Journal des Mines. Citizen Hauy, therefore, difcovered by geometry what I confirmed 

 by chefnical analyfis ; and this fatisfaflory agreement, between two fciences apparently fo 

 remote from each other, affords a proof of the truth and certainty of their refpe£tivc 

 principles. 



I fliall now proceed to relate the experiments by means of which I afcertalned the nature 

 of the principles of the chryfolite, and determined their proportions. 



Experiment i. Two hundred parts of chryfolite in cryftals being fubjeded to the aftion 

 of a ftrong heat for one hour, loft their yellow colour without undergoing any change of 

 form or tranfparency. They then rcfembled rock cryftal, and had loft only one two- 

 hundredth part of their weight. 



Experiment 2. One hundred parts of pulverifed chryfolite were mixed with the fame 

 quantity of concentrated fulphuric acid, and about four hundred parts of diftilled watet; 

 the mixture immediately became hot, and alfumed the confiftence of thick foup. Nearly 

 tlie fame quantity of water as before was added, and the whole was boiled for feveral 

 hours in a matrafs with a long neck. The mixture being then diluted with much water 



* " Colore haec gemma gramineo viridl flavo, feu aurantiorum, omnibus gemmis imo cryftaJlo montane 

 moUior, chalybc rafilis, calcinata colorum tranTparcntiam perdit, albefcens, pondcre ct parum diminuitur j 

 ccrtls circumftantiis per fe liquabilis in vitrum opacum album ; in eo etiam a reliquis gemmis diftincfta, quod in ' 

 momento fufionis eodem modo phofphorefcat ut terra aluminaris, vel fpathum gypfofura. Cum borace inftar 

 fmaragdi in fufionibus fe habet, qu^m tamen gravitate fpecificj fuperat in proportione ad aquam ut 3.600, vel 

 J. 700 : 1. 000. Figura dicitur efic polygona feu quadrangularis ; occurrit etijra filiciformis, rotundata, ia 

 Bfafvlia." 



3 H 2 was 



