32 Dr. Kane on the Compounds of Ammonia. 



II. OF A NEW BASIC SULPHATE OF COPPER. 



Having found, as In the preceding instance, that by the action of water on 

 the ammoniacal compounds of the metals under examination, there was gene- 

 rated a series of basic salts, I became desirous of re-examining some of those 

 already known, particularly in order to determine the function of the water 

 which they constantly retain. For this purpose I prepared several portions of 

 the sub-sulphate of copper, and I soon perceived, that, according to the quantity 

 of alkali employed in the precipitation, where potash had been used, there were 

 two distinct precipitates produced, the one of the bluish green generally de- 

 scribed, the other of a clear grass green, resembling that of hydrated oxide of 

 nickel. When ammonia was employed, the former alone was produced, and the 

 formation of the latter I found to occur where the whole of the copper had been 

 thrown down, but the liquor had not yet begun to react alkaline. It is singular 

 that this basic sulphate had not been observed by any of those chemists who 

 examined the common species. I found it in the first instance accidentally, but 

 I have since seldom failed in preparing it completely pure. 



It was analyzed as follows : 



A. 7-124 grammes were dried until all traces of watery vapour ceased ; there 

 remained a brown powder 5.614, or 78.8 per cent. This was dissolved in 

 muriatic acid, and precipitated by chloride of barium ; there was obtained 

 1.851 of sulphate of barytes, indicating of sulphuric acid 8.94 in 100 of green 

 powder. 



B. 3.877 grammes were exposed to a temperature of 300° F. in an oil-bath, 

 until it ceased to give off water, it then weighed 3.460. The oil-bath having 

 been removed, the drying was completed by the spirit-lamp, at a temperature 

 of about 500°, after which there remained 3.042. There had been thus driven 

 off: 



In first period = 10.76 per cent. 



In second period = ] 0.52 



Water in 100 of powder = 21.28 

 The composition resulting is : 



