, 8U /J with Sulphur and Oxygen. 359 



The whole, being boiled to dryness, that the metal might c • 

 oxidized, the glass vessel was heated to redness, and weighed 

 46-6500. Mow the weight of the 



Glass was = WW* 



Metal = 8-504d 



Oxygen = JJW80 



46-6500 



But 8-5015 : 0-96SO :: 10 : 1-1382. Therefore in this experi- 

 ment 100 parts of metal combined with 1 1-382 parts of oxygen. 

 The principal part of the mass had a high colour (like that of gum- 

 rut) but some red streaks were perceptible ,0 k ; and wher .viewed 

 to a particular position, the whole mass appeared red, like *e rust 

 of iron. Tins might proceed from a portion of iron contained in 

 the acid employed? anil which was rendered visible by the great 

 quantity of acid boiled over the metal. The experiment being 

 Repeated, 100 parts of metal united with 1 1;2 7 5 parts of oxygen. 

 The whole mass, as in the first experiment, when he d in a particular 

 portion, had a tile-red colour. The acid emp oyed was pure, and 

 therefore could not communicate any iron to the oxide. 1 he mass 

 was exposed to a stronger red heat than in the fomier expenment. 

 This circumstance, together with the purity of the acid employed 

 may account for the smaller per centage of oxygen which was found 

 to unite with the metal. . 



Experiments made in this way are not liable to any loss. As the 

 second seems most worthy of confidence, we may reckon the 

 quantity of oxygen which unites with 100 parts of bismuth at 

 11-275. 



3. With Sulphur and Oxygen. 



Into a glass capsule, weighing Sl-*6% were put IQ-JWhof 



metallic bismuth, which were boiled w ni sulphuric acid to a g rey 

 mass. This was sprinkled with nitric acid, m order to convert the 

 whole into sulphate of bismuth. The boiling was continued t 11 

 the whole mass became white/and then the mute was ^exposed to 

 a strong heat, in such a manner that the sulfuric :acid driven oft 

 could r^t condense in the mouth of the vessel. 1 he mass, when 

 cold, inclined a little to a grey colour, and weighed (including the 

 ml) 48-337- Thus we see that 10 parts of metal had increased 

 in weight 6-455. Of this increase, 1 ■ 1 275 was oxygen, and 5 32? 

 Sulphuric acid. Now this quantity of sulphuric acu con ams 

 3-1946 of oxygen. But this number is not a multiple ot the oxygen 

 in the metal by a whole number. This c.rcum>.ance, combined 

 With the colour, led me to .uspect that the metal had not been 

 Oxidized. On that account nitric acid was added, v,huh occasioned 

 the emission of red fumes. The whole being bo, led lor some 

 £ne, evaporated to dryness; and exposed to R gentle red heat, 



3 



