84 Formation of Yy rites. — On Phofphcrus. 



dark grey colour, formed in the coutfe of a very long time, on fome filvcr images, ih a 

 chjrch at (I believe) Seville. This incruftation he found to be a compound of filver with 

 lUlphur, ox, in other words, vitreous filver ore. The fame principle is the caufe of the 

 ftirnirti which filver plate contrails with fo much eafe, particularly in great cities ; for this 

 tarnifli is principally a commencemeat of mineralization on the furface, produced by the 

 sulphureous and hepatic vapours difperfed throughout the atmofphere, infuch places. 



To Mr. Wifeman's obfervations we are much indebted, as they make known the 

 iccent and daily formation of martial pyrites, and other ores, under certain circumftances. 

 It is not to be fuppofed that fuch effecfts are local, or peculiar to Difs Mere ; on the 

 contrary, there is reafon to believe that fimilar effeds, on a larger fcale, have been, and are 

 now, daily produced in many places. Tlie pyrites in coal mines have, probably, in great 

 meafurc thus originated. The pyritical wood alfo may thus have been produced ; and, by 

 the fubfequent lofs of fulphur, and oxydation of the iron, this pyritical wood appears to have form- 

 ed the wood-like iron ore which is found in many parts, and particularly in the mines on the 

 river Jenifei, in Siberia. In fhort, when the extenfive influence of pyrites in the mineral king- 

 dom, caufed'by the numerous modifications of it, in the wayofcompofition and decompofition, 

 is confidercd, every thing which reflefts light on its formation becomes interefting ; and I 

 cannot but regard as fuch, the cffedls \\hich Mr. Wifeman has obfcrved in the Mere 

 of Difs. 



Widi great refpeft, I remain, &c. 



CHARLES HATCHETT. 

 The Right Hon. Sir Joseph Banks, Bart. 

 K.B. P.R.S. &c. 



VIIL 



MJlraR of Experiments and Obfervations on the internal XJfe of Phofphorus. By AlphQU- 

 SUS Lf.ROl, Profejfor at the School of Medicine in Paris*. 



1. X HE internal adminiftration of phofphorus in fuch difeafes as cxhauft the vital 

 powers, appears to give a certain degree of atSivity to the energy of life, and afFord fpirits 

 to ^he patient without raifing the pulfe in the fame proportion. The author relates feveral 

 cafes in his own pradtice. Among others is the following. He was called to a woman at 

 the point of death, who was exhaufted with weaknefs after three years' fjcknefs. He yielded 

 to the preffing intreaties of her huftand, who earneftly defired that he would prefcribe 

 fomething. He compofed a draught confifting of fyrup diluted with water, which had 

 remained upon the fticks of phofphorus. She was much better the following day, and 

 continued to recover for feveral days afterwards. She died about fixteen days fubfequent 

 to this prefcription. 



• From the bulletin df the Socictti Philomathique, copied into the Journal de Phyfique, IV. N. S. 40*. 



2. H« 



