436 Mr. W, Hcrapath on Cadmium. [June, 



or wax ; and kept the end containing the metal in the red heat 

 of a common fire-grate until the whole of the cadmium was sub- 

 limed into a part of the tube very near where it was red-hot. 

 After throwing out what remains in the bottom (and which may- 

 be done without danger of losing any of the sublimate, as that 

 adheres very firmly to the glass), introduce some wax, and heat 

 it gently ; while the wax is in the act of burning, the metal will 

 melt and form a button, if assisted with slig-ht agitation ; it 

 should be allowed to cool before it is taken out. Its colour is 

 such that those of my friends who have seen it supposed it to be 

 silver ; but when compared with a piece of that metal it has a 

 blue cast. The bottom and sides of the button are covered with 

 facets, having exactly the appearance that it would assume if it 

 had been struck on every part of the surface with a small ham- 

 mer. When examined with a strong lens, the superficial crystals 

 resemble stars/ each having a nucleus from which six spiculge 

 radiate. I have inclosed a lamina for your examination ; you 

 will perceive that it is more malleable than Stromeyer found it ; 

 it is very probable that his contained a little zinc. The specific 

 gravity at 62° of the specimen from which this piece was cut, 

 was 8-677. 



As to the weight of the atom, Stromeyer calls it 6*9677, but 

 his analysis gives 



Carbonate 7*05 



Sulphate 7-05 



Nitrate 6-93 



Chloride 7-15 



Phosphate 6*89 



Oxide 6-96 



Average 7*005 



From this, I think, we might infer, that the true number is 7, 

 at least in the absence of a greater number of experiments. He 

 has stated. Annals, vol. xiv. p. 271, that *' the precipitate formed 

 from muriate of cadmium by carbonate of ammonia is insoluble 

 in an excess of carbonate." This has been contradicted by the 

 late Prof. Clarke, Annals for March, p. 196. In order to set the 

 question at rest, I made some muriate of cadmium, both of the 

 substances being pure; then put 1-lOth grain into two watch 

 glasses, adding a few drops of water to dissolve it. I poured 

 upon it a solution of carbonate of ammonia (saturated at 60®) 

 until it amounted to 227-17 gr. it appeared to have dissolved a 

 part ; but having stood 12 hours, it was decanted, washed, and 

 kept at 150° long enough to evaporate any carbonate of ammonia 

 left in it; the residue was '08. Now as '1 grain of muriate of 

 cadmium is equal to -084 carbonate, supposing the '004 of loss 

 to be dissolved, instead of the unavoidable errors of experiment, 



