622 FOODS AND FOOD ADULTERANTS. 



also to see what strength of powder could be obtained by lessening the 

 quantity of filling used, I compounded a number of powders from com- 

 mercial cream of tartar and soda, using different proportions of starch, 

 and determined the per cent, of carbonic acid, both total and available, 

 in each. The chemicals used were dried before mixing, and the latter 

 operation very thoroughly performed. 



Formula No. \, containing 20 p.cr cent, starch filling. 



Cream of tartar ounces.. 8 



Baking-soda do.... 4 



Corn starch ...do... 3 



Total carbonic acid per cent.. 13. 39 



Available carbonic acid do.... 11. 96 



Formula No. 2, containing about 15 per cent, starch filling. 



Cream of tartar ounces.. 8 



Baking-soda do.... 4 



Corn starch ...do... 2 



Total carbonic acid per cent.. 14.60 



Available carbonic acid do 12.89 



Formula No. 3, containing 10 per cent, starch filling. 



Cream of tartar ounces.. 6 



Baking-soda do.... 3 



Corn starch do... 1 



Total carbonic acid per cent.. 15. 10 



Available carbonic acid do 13.70 



From the above it will be seen that most excellent results were ob- 

 tained with these powders, made up by simple formulae. The powder 

 containing the least percentage of starch, Formula No. 3, gave 13.70 per 

 cent, of available carbonic acid, nearly 1 per cent, more than the highest 

 result obtained in any of the commercial samples. To be sure these 

 powders were freshly made, and would doubtless deteriorate on keep- 

 ing, those with the lowest amount of starch perhaps more rapidly than 

 the others, as most of the commercial samples containing less than 10 

 per cent, of starch show low percentages of available carbonic acid, No. 

 5505 being an exception. But these prepared samples establish very 

 completely the point I desired to make, that baking-powders can be 

 readily made up by simple formula) that will compare favorably with 

 the best samples obtainable in the market. 



These samples, however, were all made with icell-dried ingredients, 

 as they would be by a manufacturer. The next question is, whether a 

 powder could be made which would keep without serious deterioration, 



