7^ ANALYSIS OV AMPnJ^etE. 



«/ Cape fie foroied of a multitmle of t.-niitiKr, which eive them a cTia- 

 8cnV»ea. • toyaiit appeaijuice. 1 heir tract nvf is tronsverst*, and im- 

 evex). Spec, j^rav. 3'25. Thi'V 8<.'iateli j^luss; and strike 

 fire with stetl, but net cusily. '["heir primitive form 

 niid integrant particle are ai> oblique prism terminated by 

 rlMMirbii. lifcfore the h}<>\vpi|>e they naelt intaa bl>iek p;la!*s. 

 It breaks pretty readily ; bt«t is not eat;y to redw:e to pow- 

 der, more on aeeoimt of the Flexibihty of its laminse than 

 its hardness; The coarse |>c*wder is of a duU gfeen, the 

 very fine powder of a greonish gray. 



When exposed to a red h?«t it Tofes about 2^ per ceot, 

 and retains on cooling a red^iish hue from the oxide of irwi 

 contained in >t. 

 Comparison. The prineipal object of Mr. LaTj:;ier m an»lysin« thj» 



",*^"^"'^*''"° siTbstaiice was to compare the r.atnre and pr<=vportions of 

 the co-.rj.Oi ent parts of amphibole and actmote, between 

 which €i*}stallography finds a perfect re&embhm^e- Thoa.«^b 

 the resufts do not exliibit a resenibiance ro romplete; Mr. 

 La»crier d'Oes not think they ^Itffer so sensibly, but, some 

 resemblance may be fo^jod between the t^o stones. If 

 the proportimis of the su))8tanre that compose tbetn be not 

 ♦sactly the samp", at least tve find in them the sanne priw- 

 erples*; and it appears no l^s established, that the differ- 

 ences found in them arc not any of those that influence 

 the form of the crystals. The absence of chrome and' of 

 an atom of potash in the nmphibo'.e; the preseRce of at 

 larger portion of.alnmine, ai^d a double quantity of iron in 

 the same stone ; and lastly, some other differences in the 

 proportions of the remoining- principles; do not essentially 

 produce any very remarkable ehanj^e in the crystal lizHtioUj^ 

 accordiuLf to the observations of the most celebrated mine- 

 ralogislsf, li may not be useless to observe, that the dif- 

 ference between the proportions of the absolute quantities 



* Not vhoth'. C. 



+ That is to say, wliPtlicr a stone contain ii per cent of oxide of 

 ■imn, or shore twice*, its much ; ftbost- 10 per «inU ef HlajncsJa, or 

 fiimoKt S<^; near S jhv <-cnt of ahinaine, or not 1 per ccBk; 3 per ecnt 

 ? of ehr*»n»f, or not a sinejSe iitom : the form of its crystals may be pre- 



cisely the satne, ai:<l \luy may exhibit ho tiifTereuce to thtir mcTst ex- 

 peft ilisytcloru,. C. 



•f 



