Defcr'tption of fame new Fojfils, ai.i 



proof of thi5. Another argument in favour of this fuppofition may like wife be drawn 

 from the uniform lofs of weight which has been obferved in burning charcoal in pure air 

 or oxigen gas ; that is to fay, the weight of the carbonic acid produced has never been 

 found equal to that of the oxigen and charcoal confumedi; this deficiency I make no doubt, 

 has arifen from the produftion of water which was afterwards held in folution by the car- 

 bonic acid gas, and could not therefore appear in its natural ftate. That mofl; gafes con" 

 tain a large proportion of water at the common temperature of the atmofphere can hardly 

 be doubted, although it may be very difficult to eftimatc the quantity, for the drjeft gafes 

 expofed in clofe bottles to freezing mixtures, will be found to depofit a confiderable quan- 

 tity of moifture, which will again difappear on raifing the temperature. It is not impror 

 bablc, therefore, that water may be frequently produced without our being able to detecl 

 it. It is no doubt in a great meafure from this impurity in the charcoal, that .all the gafe» 

 obtained from mixtures containing it, are fo uncertain and variable in their properties. 

 Wooltvichy Aug. 19, 1 80 1. 



II. 



Short Notice concerning the Properties and external CharaElers of fame new Pojfilsfrom SweSeti 

 and Norway ; together with fome Chemical Remarks upon the fame. By Mr. D'AndraDA. 

 In a Letter to Mr. Beyer ^ Mafier of the Mines at Schneeburg. 



(Concluded from page 1^6. J 



IX. WERNERITE. 



JLTS colour lis a *iedium between the piftaccia-green and Ifabella-yellow, of different 

 fhades of yellow. Inwardly its luftre is of the fattifli kind, approaching to that of the 

 inotherrof-pearl, fometimcs in a high degree refplendent, and fometimes a little chatoyant, 

 but without any diftinft play of colour. In fmall fragments it is very tranfparent ; and its 

 fpecific gravity is 3.6063. It cuts glafs, but gives little fire with fteel, and can be fcratched 

 by the .common feld-fpar. Its texture is fomewhat curvilinearly foliated, and when thtf 

 lamcllx are confiderably curvilinear, the fraGure appears chatoyant. The laminae feem to 

 crofs each other twice in an oblique direction. The crofs frafture is uneven and fiitt; 

 fplilitery; «nd its fragments are fplintery, with fliarp edges and pointed. Werneritc; 

 occurs in mafles and cryftallized. The cryftals are low, hexahedral columns, with tetra- 

 hedral terminations, having their terminating faces impofed on the lateral edges. In thofc 

 fpecimen's, which are found in lumps or mafles, the form of aggregation is large and coarfe 

 granular, and very much concreted. This ftone readily frothes upon charcoal before the" 

 blow-pipe, and its edges exhibit an opaque, white, imperfefl enamel. It occurs in th6 

 iiron-mines Norfho and Ulrica, in the Arendal territory in Norway, and alfo in Cam- 

 polongo, in the Lewindale, in Swiflerland. This foflil. bears great refemblance to the 

 adamantine fpar in its colour and luftre. 



