478 Intelligence and Miscellafieaus Articles. 



out any hypothesis, the proportions in which the bodies combine 

 could be deduced. According to M. Berzelius, the proportions are 200 

 of oxygen to 76*52 of carbon. According to the recent experiments, 

 above-mentioned, by MM. Dumas and Stas, the result will be very 

 different, for they gave by the combustion of naphthalin, four ex- 

 periments, 75*21, 75*01, 75*08, 75*07; by the combustion of cam- 

 phor, three experiments, 75*1, 75'1, 75*0; by the combustion of 

 benzoic acid, two experiments, 75*09, 75'03; by that of the native 

 graphite Of Ceylon, three experiments, 74*91, 75*05, 74*99; by 

 artificial graphite extracted from an iron which contained most of 

 it, two experiments, 74*87, 74*90. " All these numbers," M. Dumas 

 remarks, " agree in showing that the true atomic weight of carbon 

 is 75, and not 76*52. There is consequently an error in the indis- 

 pensable elements in fixing the formulae now employed in organic 

 chemistry. That is to say, there will be many formulae to modify, 

 many analyses to repeat, especially of those substances which are 

 rich in carbon, in which very considerable errors may have been 

 committed." 



M. Dumas adds, that the Academy will remark with interest, that 

 this long and laborious series of experiments has brought us to the 

 atomic weight indicated by Dr. Prout, who. had long supposed that 

 the atomic weight of charcoal was exactly equal to six times that 

 of hydrogen, or 12*5 x 6 = 75, which is the number given by 

 the mean of our results. If, as believed by Prout, and as now ap- 

 pears very probable, all atomic weights are multiples of that of hy- 

 drogen by whole numbers, there will be many things to rectify in 

 the atomic weights at present adopted. Future experiment will de- 

 cide this point, but it is evident that they must be submitted to a 

 serious verification. 



" The Academy," continues M. Dumas, " will remark also with 

 interest, that the atomic weight -of carbon which results from these 

 experiments agrees much better than the former with the old ana- 

 lyses of Iceland spar, arragonite and marble, made by Thenard and 

 Biot, as well as with the densities of oxygen and carbonic acid, de- 

 termined either by MM. Biot and Arago, or by M. de Saussure, 

 whose results also approximate to ours with regard to the combus- 

 tion of charcoal." 



M. Boussingault has communicated some analyses of bitumen, 

 which entirely agree with our results." — L'Institut, No. 347. 



1 



PYRRHITE — A NEW MINERAL. 



Only one example of this substance is known, and occurs in a 

 splendid drusy cavity of felspar, which is in the possession of Vice- 

 President Perowski, of Petersburgh. While the cavity chiefly con- 

 tains felspar crystals several inches in size, finely defined, and of an 

 ochre-yellow colour, it likewise includes six-sided tables of reddish- 

 white, pearly lithion mica ; white translucent crystals of albite ; 

 crystals of clove-brown rock-crystal ; and a few white topazes. The 

 crystals of the new mineral are superimposed on the felspar, are 



