Intelligence and Miscellaneous Articles' 155 



On examining the action of hypophosphorouB acid on the salts of 

 copper, the author found, that under certain circumstances a com- 

 pound was formed which possessed all the characters of a definite 

 hydruret of copper ; it may be prepared in the following manner :— 

 Dissolve one part of hypophosphite of barytes in water, and pre- 

 cipitate the barytes, perfectly, by sulphuric acid ; add to the filtered 

 liquor 0*8 of a part of sulphate of copper in a concentrated solution. 

 The mijtture is to be heated to a temperature not exceeding 158° 

 Fahr. ; the liquor assumes a green tint, and then a precipitate is 

 formed, which is at first yellow, but gradually deepens till it becomes 

 of the colour of kermes ; at this point of the operation small bubbles 

 of hydrogen are often observed to be given out ; in this case the 

 liquor must be quickly cooled, and the precipitate is to be washed in 

 an atmosphere of carbonic acid, with water free from air ; it then 

 only remains to dry the substance by pressure between folds of 

 filtering paper. 



With respect to the theory of this operation, the author remarks, 

 that the first eflfect of heat is to reduce the sulphate of copper to 

 the sulphate of suboxide by the agency of the hypophosphorous acid, 

 the salt remaining in solution. This formation of a salt of suboxide 

 of copper may be proved by the addition of a few drops of sulphu- 

 rous acid, which in a short time precipitates red-brown sulphate of 

 suboxide. If the heat be continued, the salt of copper is also re- 

 duced, and a hydruret of copper is formed, which corresponds in 

 composition to the suboxide of copper. 



This reaction is never quite perfect ; even when there is an excess 

 of hypophosphorous acid, there alwaj'S remains some oxide of copper 

 in solution when operating in the mode described ; but if the propor- 

 tions of the mixture, the nature of the salts of copper and the condi- 

 tions of temperature be changed, the products of the reaction are 

 diflFerent, and these the author proposes to describe in a future me- 

 moir on the hypophosphites. 



Hydruret of copper is a powder of a deep brown colour ; when 

 dry it begins to decompose, though slowly, at 131° Fahr. If it be 

 heated in an open vessel to 140°, the decomposition is often sudden, 

 and occurs with a kind of whistling throughout the mass, which is 

 quickly projected. In the moist state the hydruret of copper is 

 rather more stable ; in vacuo it loses hydrogen ; when exposed to the 

 air it is gradually converted into a yellow powder, which is suboxide 

 of copper; this oxidation occurs more rapidly if the hydruret be 

 moistened. In a perfectly dry air this substance blackens in a day's 

 time, probably because a little oxide of copper is formed. 



Dry hydruret of copper inflames in chlorine with the formation of 

 thick vapours, which condense into flocculi of perchloride of copper ; 

 similar incandescence occurs in bromine ; hydrochloric acid exerts 

 a very remarkable action on hydruret of copper ; the concentrated 

 acid, even cold, produces a brisk eiFervescence of hydrogen, and pro- 

 tochloride of copper is formed. If too great excess of acid be not 

 employed, a portion of this salt crystallizes in small scales, which are 

 readily distinguishable among the small residue of copper. On the 



