314 METALLIC OXIDES. 



but at present we must be content with the mean or average 

 numbers. 

 ... \ \ How ox- 5 * Yettnw oxide of antimony. If antimony be digested 

 kkof anti- with the nitro-muriatic acid, or with fuming nitrous acid, and 

 tinK^di^ested tne solution be evaporated to dryness, and then sufficiently 

 with nitro- heated to drive off the acids without igniting the mass, 

 ftimin^nitrmis a ve ^ ow P° w der is obtained, which is often crystalline, and, 

 acid, the dried if strongly heated in the fiflfc becomes white, and consequently 

 massisjeiiow. d | d not owe its ( ye ij ow ) co lour to an adulteration with the red 



oxide of iron. 



100 p, of me- When I made this experiment in a glass phial, weighed, and 



oxide Vt 13 ° maa * e use °* me fuming nitrous acid, I obtained as much as 



131 p. of a yellow crystalline powder ; but when I had oxiu-cd 



the metal by means of the nitro-muriatic acid, the result did 



not exceed 129 or 130 p. of oxide from 100 p. of metal, and 



new cohobations of acid upon the yellow oxide did not increase 



the weight. The addition of 30 or 31 p. of oxigen does not 



agree with any proportion of those which I had before found, 



supposed to and * began to suspect a combination of two ditferent degrees 



be n com- of oxidation had been formed, and that this combination could 



SXenfde tW ° not be farther oxlded b Y meanS of acids ' 



grees ofoxida- I shall not mention the various unsuccessful experiments I 



lW)n, made to clear up this intricate subject, but shall speak only of 



those which afforded more satisfactory results. 



Antim. oxided \ mixed powdered antimony with the red oxide of mercury. 



©? mercury 6 P re P are d fr° m vei 7 P ure mercury, and heated the mixture in a 

 glass retort. At a certain temperature it took fire, and the 

 mass became red. I continued the heat as long as any mercury 

 was condensed in the neck of the retort j after which, at 

 length, there remained a deep olive-coloured powder. I heated 



coloured pow- tms w,tn S reat care in a g* ass capsule, by which treatment it lost 



tier. its olive colour, and left a straw-coloured powder in the capsule. 



-The yellow One hundred parts of this powder very strongly heated in a 



oxide loses platinacrucible,left, in different experiments, from 33 5 to 3375 

 one fourth of r , .. ..... r T , , * , 



its oxi«en by parts of white oxide of antimony. In order to determine the 



heat, and be- nature of what had been dissipated by the heat, the experiment 



eomes white ... ,, . , , . . 



oxide. Wltn tne y e "O w oxide was repeated in a small glass retort, 



with a small apparatus for collecting the gas. When the re- 

 tort began to be strongly ignit/id, a gas was developed, and 

 when this ceaied tBe retort was removed from the fire. The 



residue 



