23G Intelligence and Miscellaneous Articles. 



PHOSPHATE OF COPPER FROM HIRSCHBERG, ON THE SAALE, IN 

 RUSSIAN VOIGTLAND. ANALYSED BY KUHN. 



This mineral is of a nodular appearance ; the internal structure is 

 concentrically fibrous, with conchoidal fracture ; in colour it resem- 

 bles malachite. Its specific gravity cannot be determined on account 

 of the impurity of the material. The matrix is a brown iron stone, 

 interspersed M'ith veins of quartz, and containing here and there 

 groups of quartz crystals. 



The analysis was gone through in the following manner : some of 

 the purest pieces, amounting to 0"407 gramme, gave 0'031 loss by 

 ignition. After its solution in dilute nitric acid, there remained 

 0'030. The whole loss fi'ora ignition amounted, therefore, to 7'62 

 percent; and the foreign matter to 7"37. Now since ri47 of 

 pure matrix, by ignition, gave 1'031 of residue, so must 7'37 of 

 matrix, brought to a red heat, have been obtained from 8"20, M'hich 

 was unignited. Thus, in the total loss from ignition, 0"83, which 

 resulted from the matrix, are reckoned. The salt of copper had, 

 consequently, from 91 '80 of its first condition, lost 6' 7 9 of water 

 = 7 "40 per cent. The oxide of copper, precipitated by boiling 

 caustic potash, amounted to 0-268, or 7r73 per cent.; and since 

 no other acid, besides phosphoric acid, could be found, this last, in- 

 cluding what was lost, must have amounted to 20'87. Another 

 portion, which weighed I '946, was dissolved in dilute nitric acid, 

 and precipitated by sulphuretted h5'drogen ; the sulphuret of copper 

 Avas then converted into oxide of copper, which weighed r354 

 = 69 '58 per cent. ; the liquor, filtered from the suljihuret of cop- 

 per, remained, on the addition of caustic ammonia, colourless and 

 clear. 



From a third unweighed portion, oxide of copper weighing 0'374, 

 and lead precipitate weighing 0'567, were obtained. If, in the last, 

 0-100 of phosphoric acid must be assumed, so, in the first experiment, 

 where 71 "73 per cent, of oxide of copper were obtained, 19'21 of 

 phosphoric acid were contained. The water, besides loss, amounted 

 to 906. 



The result was, consequently. 



Oxide of copper 71-73 69-58 71-73 



Phosphoric acid (20-87) 19-21 



Water 740 (9-06) 



The simplest proportion of the formula is 3 CuO + P 0.,^ + 1^ H O, 

 and of the quantity of oxygen 6:5:3. From experiment the fol- 

 lowing formula may be calculated : 



U (Cu O + H O) -h (li Cu O + P 0,1) : 

 or, after Berzelius's method and numbers, 



3 (Cu O + H O) -I- (3 Cu O -h Po O3). 

 Some additional grounds for this formula, as well as some analogues, 

 shall be published hereafter. — Annalen der Pharmacie, Vol. xxxiv. 

 No. 2. 



