OF ARTS AND SCIENCES. 21 



the substance is remembered. Each of these analyses was made with 

 a sample from a separate preparation, and we add the following analy- 

 sis, made early in the work simply to determine the ratio between the 

 zinc and sodium, no care having been taken to dry the substance. 



III. 0.7025 grm. of slightly moist substance gave 0.2260 grm. of 

 zincic oxide and 0.1951 grm. of sodic sulphate. 



The percentages derived from this analysis are of course of no 

 value, but it gives an atomic ratio which agrees with those from the 

 preceding analyses so closely that there can be no doubt that this 

 substance possesses a definite composition. 



Atomic Ratio of Zinc to Sodium in the Infusible Sodic Zincate. 



Zinc : Sodium. 



I. 1.03 1. 



II. 1.03 1. 



III. 1.02 1. 



A combustion of the substance showed that it contained no alcohol. 



This substance undoubtedly corresponds to the crystalline body 

 obtained by Fremy (see page 15), who assigned to it the same ratio 

 between the zinc and potassium. Laux (see page 14), on the other 

 hand, ascribed to his crystals, which were soluble in water, the formula 

 ZUO2K,, but stated that upon heating these crystals he obtained an 

 amorphous powder, which showed the ratio of 1 : 1 between zinc and 

 potassium ; that is, the same obtained in the crystals by Fremy and us. 

 We have met with no substance corresponding to the soluble crystals 

 of Laux. 



Properties. — The infusible sodic zincate crystallizes from a solution 

 in dilute alcohol containing an excess of sodic hydrate in white needles, 

 sometimes over a centimeter long, forming loose radiating groups 

 u^'jally of a conical shape, but occasionally circular or spherical. It 

 does not melt even at 300°, and is decomposed by alcohol, or water, 

 if these solvents are free from sodic hydrate, absorbs carbonic dioxide 

 from the air, but much less rapidly than the fusible compound, and 

 does not lose the whole of its water of crystallization until heated 

 above 200 ^ 



We have not succeeded in finding any other definite compound 

 among the products of the action of sodic hydrate on zincic oxide, 

 and, if any other exists, it can be only in very small quantity. 



