MINERALOGICAL SYSTEMS. 57 



fore the triangular prifm rauft be the integrant particle :* Explanation of 



,*,. r. , . . . , * , * 1 1 , r 1 T *^c figures and 



'* The forms ot the integrant particles, lays the Abbe (vol, I. formation of 



page 30) may be reduced to three, the tetrahedron or the moft cryft^ls by the 



timple of pyramids, thetriangular prifm or the mod fimple of ""^ * ^ *"^' 



prifms, and the parallelipipedon or the m oft fimple of folids, 



having parallel (ides two and two, and as four (ides are ne- 



ceflary to circumfcribe a fpace, it is evident that the above 



three forms in which the number of fides are fuccefllively four, 



five and fix, are again in this point of view the mofl fimple 



poffible." 



The phofphate of lime or chryfolite is a fubflance that has 

 given rife to much curious anecdote. It fhews in what a flate 

 Abb^ Hauy found the mineralogical nomenclature, and points 

 out the accuracy of his analytical method. Achard, achemifl 

 at Berlin had analyfed the chryfolite, and publiflied that it con- 

 tained, of filex 15 parts, alumina 64, lime 17, and of iron 

 one. This ftartled the celebrated Vauquelin, who had feen 

 Klaproth's analyfis of the chryfoh'te (the apatite of Werner) 

 containing of lime 55 parts, and of phofphoric acid 45, (pro- 

 bably the water of cryftallizalion is added to the acid.) A 

 Frenchman of the name of Launoy fent a quantity of thisfub- 

 ftance to Paris, feme of it was purchafed by the Ecole des 

 Mines, and Vauquelin was deli red to analyfe it. The latter 

 foon fufpe6led Achard iiad been milled by the name, and had 

 not obtained the proper fubftance, a mlftake the more eafily 

 made as, fays Vauquelin, " the name of chryfolite was given 

 to a great variety of ftones, fuch a^ the peridot, the chrT/fobcril, 

 the olivine, (fince found to be the fame as the peridot), ar^d in 

 general io ftones having a yellow colour." 



He foon difcovered the chryfolite fent from Spain contained 

 lime and phofphoric- acid. " I had no fooner made this dif- 

 covery, fays he, than I enquired of Abbe Hauy whether he 

 had compared the integrant particles of the chryfolite with 

 thofe of the apatite or cryftalllzed phofphate of lime. He an- 

 fwered me that he had not made tlie comparifon, but that he 

 would get his papers on primitive forms, (this was four years 

 before the publication of his work) fee what notes he had 



* Therefore the fe6lions producing the hexahedral prifm cannot 

 lead to the integrant particle : therefore all feftions, though per- 

 fectly practicable in cryftals, will not lead to the integrant particle. 



madf 



