274 M. Thenar cVs new Observations [Oct. 



©f yellow. Its texture is composed of very fine plates. It is 

 very brittle, and when the cadmium amounts only to -j—, it 

 communicates a good deal of brittleness to copper. When 

 exposed to a heat sufficient to melt the copper, the alloy is 

 decomposed, and the cadmium is volatilized completely. Hence 

 there is no reason to dread, that in the making of brass, the 

 cadmium, which may be contained in the zinc, should do any 

 damage. We see from this likewise, why tutty usually contains 

 oxide of cadmium. This alloy was composed of 



Copper 100-0 



Cadmium 84-2 



The alloy of cobalt and cadmium has a good deal of external 

 resemblance to arsenical cobalt. Its colour is very white, almost 

 silver-white. Its texture is extremely fine, and it is veiy brittle 

 and difficult of fusion. 



One hundred parts of platinum, heated with cadmium till the 

 excess of that metal was volatilized, were found to retain 117-3 

 parts. 



Cadmium unites with mercury with the greatest facility even 

 when cold. The colour of the amalgam is a fine silver- white. 

 Its texture is granular and crystalline. The crystals are octahe- 

 drons. It is very hard, and very brittle. Its specific gravity is 

 greater than that of mercury. The heat of 167° is sufficient to 

 fuse it. It is composed of 



Mercury 100-00 



Cadmium 27-78 



The results of the preceding analyses are all founded on 

 direct experiment, and not upon calculation. They are almost 

 all the mean of several experiments, differing but little from each 

 ■other. It will be found, on comparing them, that they not only 

 agree very well with each other, but likewise that they corres- 

 pond to the equivalents adopted for the elements of compounds. 

 However, M. Stromeyer proposes to give them still a greater 

 degree of precision, because he thinks, with justice, that in order 

 that equivalents may serve the science for correcting the results 

 of analyses, they must possess the greatest possible degree of 

 precision. 



Article VII. 



New Observations on Oxygenated Water. By M. Thenard. 

 (Read to the Academy of Sciences, June 16, 1819.) 



In the last observations which I had the honour of presenting 

 to the Academy on oxygenated water, I endeavoured to demon- 

 strate that water saturated with oxygen contains just twice as 



