ay JOURNAL OF THE 
tral Blatt. 97.1.857) that when a boiling solution of potas- 
sium bichromate is neutralized with sodium carbonate accord- 
ing to this equation, 
K,Cr,O,+ Na,Co,= K,CrO,+ Na,CrO,+CO, ; 
then concentrated over the direct flame and over sulphu- 
ric acid, first the doubie salt 3K,CrO,.Na,CrO, will crys- 
tallize out in the form of flat or column-shaped crystals, 
then a salt of the same composition with one half mol- 
ecule of water and finally yellow crystals of the salt 
Na,CrO,.4H,O. The sodium chromate prepared by 
Johnson which crystallized with ten volumes of water was 
not obtained. Zehenter also prepared the salts 
3K,CrO,.2(NH,),CrO, and NaNH,CrO,.2H,0O by precipi- 
tation with alcohol from the appropriate solutions. 
For my experiments the following solutions were pre- 
pared : 
1. 100 grams of potassium bichromate were dissolved in 
water and neutralized with sodium carbonate. 
2. 100 grams of sodium bichromate were dissolved in water 
and neutralized with potassium carbonate, 
3. 100 grams of ammonium bichromate were dissolved in 
water and neutralized with sodium carbonate. 
4. 100 grams of sodium bichromate were dissolved in water 
and neutralized with ammonium carbonate. 
5. 200 grams of potassium bichromate were dissolved and 
neutralized with sodium carbonate (repeating No. 1). 
6. 110 grams of potassium bichromate and 98 grams of so- 
dium bichromate were dissolved in hot water and evaporated. 
7. 67 grams of potassium chromate and 60 grams of potas- 
sium carbonate were dissolved and evaporated. 
8. 100 grams of potassium bicarbonate were dissolved and 
neutralized with magnesium carbonate. 
9. 100 grams of potassium chromate and 55 grams of sodi- 
tum carbonate were dissolved in hot water. 
All of these solutions were concentrated and then placed 
over sulphuric acid for crystalization. The crops of crystals 
were carefully separated, washed, dried between filter paper 
and analyzed. 
