EEfiEARCHES ON SULPHUR AND PHOSPHORUS. 3| 



tjons of the first two injrredients are very nearly reversed. 

 Klaproth obtained from 0*4 to 0*5 of copper, and from 

 0*22 to 0'27 of iron. This renders it obvious, that the tw6 

 ores were not in the same state, i have httle doubt, that 

 the difference, however, is merely apparent, and that it 

 arose, altogether, from a quantity of iroi; pyrites, and 

 perhaps also of arsenic pyrites, which I could i>ot separate 

 from the gray cop[)er ore which I examined. Both of these 

 minerals could be distinctly seen in many of the specimens, 

 intimately mixed with the gray copper ; and I have no doubt, 

 that the same mixture existed, even \n those specimens 

 which were selected as purest. The diirerenct in the pro- 

 portions of copper and arsenic, ol)tained by Khiproth* in 

 his various analyses, is so considerable, as to lead to a sus- 

 picion, that even his specimens, ia all probability, contained 

 H mixture of foreign matter. 



IV. 



Researches on the Oximuriatic Acid^ its Nature and Comli* 

 nations ; and on the Elements of the Muriatic Acid, With 

 some Experiments on Sulphiir and Phosphorus, made in 

 the Laboratory of the Royal Institution, By M. Davy, 

 Ei^q. Sec. R, S. Prof Chem. R. I. F. JR, S. E. 



f Concluded from vol. XXF/I, p. 537. J 



JL SHALL occupy the time of the society for a few minutes 

 only, for the purpose of detailing a few observations con- 

 nected with the Bakeriaii lectures delivered in tlie last two 

 years; particularly those parts of them^ relating to sul- 

 phur and phosphorus, which new and more tninute inqui- 

 ries have enabled me to correct or extend. 



I have already mentioned, that there are considerable Difference!! in 

 difi'erences in the results of expeiiments made on the action ^^^e results »f 



