BAKING POWDERS. 

 IV. Alum powders. 



587 



V. Unclassed powders. 



SPECIAL REMARKS. 



Sample No. 6. This sample shows strong reactions for ammonia, soluble sulphates, 

 soda, and potash. Its aqueous solution, rendered ammoniacal before filtering, reduces 

 silver from a crystal of the nitrate, as a bright coating on the glass. It would have 

 been classed among the cream of tartar powders had it not shown altogether too much 

 soluble sulphates. Shaken with absolute alcohol it renders this slightly alkaline; 

 boiled with water the powder gives a decidedly alkaline solution. It contains some 

 alumina. 



Sample No. 18. This gave strong reactions for ammonia, soluble sulphates, soda, 

 and potash. Tartaric acid was extracted from it by shaking with absolute alcohol. 

 It may contain some cream of tartar, but has too much soluble sulphates to warrant 

 placing it among the cream of tartar powders. 



Sample No. 22. This powder gave strong reactions for alumina, soluble sulphates, 

 and soda. Neither potash nor ammonia was present. The label stated that it con- 

 tained grape (tartaric?) and orange (citric?) acids, combined " with natron, bicarb, 

 soda, and corn starch," and the analysis indicated the presence of tartrates and cit- 

 rates, as well as much alumina, which was abundantly found in the aqueous solution 

 of the powder even after boiling with the nndissolved residue. Alumina in a soluble 

 form was also extracted in considerable quantity by water alone from bread made 

 with this powder. Apparently, the organic acids kept it in soluble condition. Since 

 neither potash nor ammonia was present, the alumina appears to have been added in 

 the shape of sulphate of alumina, or else of soda alum. 



After washing away the starchy matter with chloroform and examining the residue 

 under the microscope in polarized light, crystalline fragments of a singly refracting 

 substance were observed in abundance, together with doubly refracting crystalline 



360 pt. 5 3 



