238 ANNUAL OF SCIENTIFIC DISCOVERY. 



Crude. Refined. 



Copper, 99.4000 99.4800 



Sulphur, 0.3140 



Lead, 0.3620 



Silver, 0.1000 0.1000 



Bismuth, 0.1440 0.0480 



Gold, 0.0008 0.0008 



Tin, trace, 



Antimony, " 



Loss, 0.0411 0.0089 



The lead, with a trace of arsenic, proceeded from the process of refining ; 

 and it is found, by experiment, that the small proportions of antimony, 

 arsenic, gold, silver and lead, do not explain the want of ductility of the 

 copper. The bismuth, then, only one- third of which had resisted oxida- 

 tion, is the sole cause of the loss of ductility. M. Level has proved the 

 correctness of this conclusion by preparing different alloys. It is remark- 

 able that bismuth, which has so many points of resemblance to lead, should 

 be so different in the above respect. It is important to examine for bis- 

 muth the coppers of commerce, in order to search out the cause of the 

 peculiar mechanical and chemical qualities often found even in copper of 

 excellent appearance. 



RESEARCHES ON FLUORINE. 



The following paper on fluorine has been read before the French 

 Academy by M. Freray : 



Some years since M. Louyet announced to the Academy several 

 important facts respecting fluorine, hydro-fluoric acid, and the fluorides. 

 According to M. Louyet, fluoride of mercury, heated in tubes of fluoride 

 of calcium, was decomposed by dry chlorine, and gave fluorine ; anhydrous 

 hydro-fluoric acid prepared by the method mentioned by M. Louyet did 

 not attack glass ; and, moreover, the equivalent of fluorine determined by 

 Berzelius should be replaced by a new number. 



Not having considered the experiments of Louyet altogether satisfactory, 

 I determined, says M. Freiny, to submit the whole to a careful exami- 

 nation. Following, in my experiments, such men as Gay-Lussac, 

 Thenard, Berzelius, and Davy, I could not anticipate that any fortunate 

 scientif% accident might lead me to the immediate discovery of fluorine ; 

 but I knew that a general study of the fluorides would, under any 

 circumstances, be very interesting to scientific men ; it would complete the 

 history of a series of compounds, hitherto but little known, and which, 

 notwithstanding, play an important part in geological phenomena ; it 

 might indicate the direction which should be followed to attain the 

 discovery of fluorine. This hope has sustained me through the lengthy 

 work whose principal results I am about to describe. 



