180 
In the following lines we shall now state the results of experi- 
ments made with a view to get more closely acquainted with the 
compounds formed in “dissolving” zinchydroxide in NaOH i.e. the 
zincates of sodium, and accurately to determine their range of 
existence. Similar investigations concerning the correspondent com- 
pounds of some other metals are in progress. 
We shall now briefly summarize the data known up till now 
concerning the sodium-zincates : 
By means of solving ZnO in a hot NaOH-solution, followed by the 
addition of aleohol, Comey and Lorine Jackson ') obtained two 
products, to which they ascribe respectively the formulae: 
H, Na, Zn, O,17 H,O and HNa ZnO, 7 H,0. The first compound has 
a melting-point of 100°, the second proved not to melt even at 300°. 
Forster and GüNrner ®) found only one compound viz. the formula 
OH 
Zn 3 H,O. It formed white silky-glossy needles. 
O.Na 
Herz *) precipitated a solution of Zn SO, of known concentration 
with a KOH-solution and then investigated how much base is 
required once more to solve the Zn (OH), that is formed. It appeared 
that to 1 gram equivalent of Zn, 6 gram equivalents of OH were 
required. 
Hanrzscu *) denies the existence of sodium-zincates on the ground 
of conductivity measurements and attributes the solution of Zn (OH), 
in NaOH to the forming of a colloidal solution. 
Jorpis °) observes that in the long run, crystals of the composition : 
Zn (ONa), arise in the cupron-element, in which zine is found as a 
negative pole in a solution of NaOH. 
Finally it should be mentioned, that RuBeNBAUER *) and Woop ‘) 
have determined the proportion of the number of gramatoms Zn 
and Na in a solution of Zn (OH), in NaOH; these observations can 
teach but little regarding the existence of definite compounds. 
We see from these data of the literature how vague our knowledge 
about such comparatively simple compounds still is. 
The equilibriums that may arise in an aqueous solution between 
1) Amer. Chem. Journ. 11, 145 (1889); Ber. d. deut. Chem. Ges. 21, 1589 (1888) 
2) Zeitschr. f. Elektroch. 6, 301 (1899). 
5) Zeitschr. f. anorg. Chem. 28, 474 (1901). 
4) Ibid. 30, 289 (1902). 
5) Zeitschr. f. Elektroch. 7, 469 (1900). 
6) Zeitschr. f. anorg. Chem. 30, 332 (1902). 
7) Journ. Chem. Soc. 97, 886 (1910). 
