66 Prof. E. N. Horsford on Glycocoll, 



Hydrate of 

 It has already been mentioned, that glycocoll rubbed with pul- 



verized hydrate of baryta, in a mortar, becomes almost instanta- 

 neously semifluid. Upon diluting the solution, and setting aside, 

 after a time crystals containing both baryta and glycocoll were 

 deposited. The salt was not analyzed. Its composition, in all 

 probability, corresponds with that of the oxyd of copper, silver 

 and lead, noticed below, and there exist, doubtless, similar salts 

 of strontia. lime and magnesia. 



Glycocoll and Oxyd of Copper. 



Gl, CuO, HO. 



This salt may be prepared by adding to a solution of glycocoll 

 sulphate of copper and caustic potash — and addition of absolute 

 alcohol, — or by dissolving hydrated oxyd of copper, with the aid 



of heat, in a solution of glycocoll, and adding absolute alcohol : 



lastly by boiling the anhydrous oxyd of copper, in excess, 

 with glycocoll. If the latter be concentrated it must be filtered 

 hot. In this case, the filtrate in a few moments is resolved into 

 a solid mass of the most exquisite cerulean blue color. More 

 carefully examined, it is found to consist of exceedingly delicate 

 needles. The addition of absolute alcohol to the concentrated 

 solution precipitates the whole salt ; to the diluted, less perfectly. 

 At 100° C. [212° F.] 0-5443 grm., at the conclusion of several 

 days, had lost 00438 grm. =804 per cent. =one atom of water. 



With 



discernible 



The analysis was made with the substance dried in the air over 

 sulphuric acid. 



Combustion with chromate of lead gave the following re- 

 sults : 



I. 0-2030 grm. of substance gave 0-1538 grm. carbonic acid and 

 0912 grm. water. 



II. 0-2373 grm. by the method of Varrentrapp and Will, gave 

 0-4762 grm. platin-salammoniac. 



III. 0*1745 grm. gave 0-0592 grm. oxyd of copper. 



IV. 0-2871 grm. gave 0*0972 grm. oxyd of copper. 

 Which expressed in per cent, give 



i- ii. III. IV. 



Carbon, 20-66 



Hydrogen, 4-99 . . 



Nitrogen, . . 12-65 . . . . 



Oxyd of copper, . . 33*85 33*92 



These give the formula C 4 H 4 N0 3 , CuO, HO, as will be 

 seen by comparing the theoretical and analytical results. 



