OF ARTS AND SCIENCES : JANUARY 31, 1866. 95 



and contained three grammes of the oxide. Although the results of 

 the analysis indicate that the temperature of the air-bath was too low, 

 they also show, by comparison with the results obtained in operating 

 with strongly ignited oxide at about the same temperature of the air- 

 bath (see p. 92), that the brown oxide is decidedly preferable in re- 

 spect to the temperature required. This was also shown by the ap- 

 pearance of the oxide after combustion, — the newly formed chloride 

 being confined, in the case of the brown oxide, to a much shorter space. 

 Results of the Analysis. — 0.1640 gramme of chloride of amyl gave 

 0.3504 of carbonic acid, 0.1562 of water, and 0.1884 of chloride of 

 silver. 



Calculated. Found. 



100. 97.210 



Analysis 4. — Used the same preparation of oxide of copper as in 

 Analysis 3, viz. the brown oxide. Temperature of the air-bath reached 

 170°. Slight carbonization occurred just at the close of the combus- 

 tion, from extending the heat backward too sobn, under a wrong impres- 

 sion that the substance was all burnt. Were it not for this circum- 

 stance, it is believed that this would have been a good analysis, although 

 the temperature of the air-bath was kept so low. That a higher tem- 

 perature of the bath is desirable, however, is shown by the fact that 

 the chloride of copper appeared diffused over a space of 2£ inches. 

 The length of the column of mixed asbestos and oxide of copper was 

 only four inches in this experiment, containing but one gramme of the 

 oxide. 



Results of the Analysis. — 0.1568 gramme of chloride of amyl gave 

 0.3195 of carbonic acid, and 0.1522 of water. 



Analysis 5. — The oxide of copper employed was of the same prep- 

 aration as that of Analyses 3 and 4. The temperature of the air-bath, 

 however, was considerably higher, ranging from 240° to 247°. The 



