270 M. Berzelins on U/auiuin. [April, 



uranium, the more especially as he found alcohol cupable of 

 extracting sulphate of uranium from it, which was not the case 

 with the salt which I analyzed. The aqueous solution of any 

 salt gave a yellow precipitate with alcohol, but the supernatant 

 liquid was colourless. 



I now prepared the double muriate of oxide of uranium and 

 potash, which may be obtained crystallized by slowly evaporat- 

 ing a liquid containing an excess of the muriate of oxide of 

 uranium. The crystals are sometimes four-sided prisms with 

 obliquely truncated extremities, and sometimes four-sided rhom- 

 boidal tables. I intended at first to have analyzed it by reduc- 

 tion in hydrogen gas, but I found that the water of crystalliza- 

 tion cannot be expelled, without carrying along with it a portion 

 of the acid, after which the salt is no longer completely soluble 

 in water. It was necessary, therefore, to perform the analysis 

 in the humid way. 1'5 grm. of the crystals, previously dried in 

 the state of powder in a temperature of 130°, dissolved in water 

 without leaving any residue. The solution, precipitated with 

 nitrate of silver, gave l'6i grm. of fused muriate of silver. The 

 excess of silver was separated by muriatic acid ; the oxide of 

 uranium was then precipitated by ammonia, and washed with a 

 solution of sal ammoniac. It was converted by ignition into 

 0*82 grm. of oxidule. From the remaining liquid, after the dis- 

 sipation of the ammoniacal salts, there was obtained 0-412 grm. 

 of muriate of potash, = 0*2606 grm. of potash. 



If the deficit be regarded as water of crystallization, it will 

 follow from this analysis that the salt is composed of 



Potash 26-06 containing oxygen 4'43 



Oxide of uranium . 83-46 " 4-47 



Muriatic acid .... 30-75 saturating capacity 9-05 

 Water 9-73 8-93 



By erperiment. By calculation. 



Potash 17-37 17-32 



Oxide of uranium. . . 55-64 55*98 



Muriatic acid 20-50 20-11 



Water 6-49 6-59 



100-00 100-00 



I have stated my results in conformity with the older theory 

 respecting the constitution of muriatic acid, that I might be able 

 to employ that acid as a standard. It is obvious that both the 

 bases contain equal quantities of oxygen, and that the saturating 

 capacity of the muriatic acid is exactly equivalent to the oxygen 

 of the two bases. The difi'erences between the experimental 

 and calculated results are trifiing, and may be safely imputed to 

 the unavoidable errors of observation. I consider the result of 



