136 Review of Dr. Thomson 



" Now 11.102+16.77+13.13+11.75=52.752. This is less 

 than the whole silica in the mineral by 0.573. As the silica in 



combination with the zirconia constitutes — of the whole, it is 



48 



obvious that in order to have the quantity of silica united to the 



zirconia in the eudialite, we must add — of 0.573=0.12 to 



4.8 



11.102, which will raise it to 11.222. 



" This gives us, 11.222 : 11.102 ::6 : 5. 9 35 8 = atomic weight 

 of zirconia V 



Does the Doctor expect any man in his senses to receive the 

 atomic weight of zirconia, so deduced ? For elaborate frivolity 

 we know nothing comparable to the above and its companion ar- 

 ticles. The whole components of the mineral eudialite, as well 

 as those of the other minerals, are undoubtedly associated by a 

 reciprocal affinity ; but our author pairs them out for his atomic 

 pantomime, with all the gravity of a French dancing-master. 



In the 10th chapter, on the atomic weights of iron, nickel, 

 cobalt, manganese, and cerium, we have sought, but in vain, for 

 any sound sample of chemical research. What is to be thought 

 of such a passage as the following ? 



" From this statement it is obvious, that when 17.375 grains 

 of protosulphate of iron are thus treated" (with a heat progres- 

 sively raised) " 7.59375 grains of water, or 7 atoms — £th atom, 

 will be driven off; 2§ grains of sulphuric acid will be converted 

 into 2 grains of sulphurous acid, which will fly off, and half a 

 grain of oxygen, which will convert the 4g grains of protoxide 

 into 5 grains of peroxide. The remaining 2\ grains of sulphuric 

 acid united with 0.28125 grains of water, the 1th atom still re- 

 maining, will be driven off in the state of fuming sulphuric 

 acidt." Though " this statement" is quite absurd in an analy- 

 tical point of view, it may be made instructive ; for it displays 

 strongly the inconvenience of the oxygen scale, compared to the 

 hydrogen. The numbers, transposed to the latter scale, run thus : 

 139 grains green vitriol lose first 60| in water (=63 — -2*); 20 

 grains of its sulphuric acid resolve themselves into 16 grains of 

 the sulphurous, which fly off, and four grains of oxygen, which 

 go to the 36 grains of protoxide, converting them into 40 of 

 peroxide. The remaining 20 grains of sulphuric acid, united 

 with 2^ grains of water, the one -fourth atom unprovided for, will 

 be disengaged in the state of fuming sulphuric acid. Will the 

 Doctor maintain that the latter view is not far more intelligible 

 than his, in which numbers with five decimal places of figures are 

 required ? And with regard to his method of determining the 



* Attempt, i, 339. t Ibid. 347, 



