14 PROCEEDINGS OF THE AMERICAN ACADEMY 



II. 



CONTRIBUTIONS FROM THE CHEMICAL LABORATORY OF 

 HARVARD COLLEGE. 



ON SODIC ZINCATES. 

 By Arthur M. Comey and C. Loring Jackson. 



Presented June 13, 1888. 



Although the solubility of ziiicic hydrate in alkalis is one of the 

 most familiar facts in chemistry, very few attempts, so far as we 

 can find, have been made to determine what compounds exist in such 

 a solution. The reason for this is not far to seek, as the results ob- 

 tained by the few M'ho have studied this subject are so decidedly 

 unsatisfactory, that they are not likely to induce others to take up 

 this line of work. 



The first important papers in this field appeared in the Annalen 

 der (Jhemie und Pharmacie in 1834, having been brought out by a 

 prize offered from the JJagen-Bucholz foundation for work on zincic 

 oxide. Of the various competitors Laux,* who was most successful 

 in his work on this part of the subject, found that a solution of zincic 

 oxide in caustic alkali, if covered with a layer of alcohol, gradually 

 deposited little shining crystals, which were easily soluble in water, 

 and, he states, contained equal molecules of zincic oxide and the alka- 

 line oxide (ZnO^Ko). These crystals were decomposed by heat, giv- 

 ing a white powder, which contained one molecule of alkaline oxide 

 to two of zincic oxide, but no analyses of either of these substances 

 are given. 



Two other competitors for this Hagen-Bucholz prize. Bonnet f 

 and Sander,^ also touch on this subject, but their results are of less 

 importance. Sander, in fact, comes to the conclusion that no defi- 

 nite compound is formed when zincic oxide is dissolved in a caustic 

 alkali. 



The next paper on the subject was published in 1842, by Fremy, § 



* Ann. Chem. Pharm., ix. 183. % Ibid., ix. 181. 



t Ibid., \x. 177. § Comptes Rendus, xv. 1106. 



