112 PROCEEDINGS OP THE AMERICAN ACADEMY 



100.0 



The percentage of phosphorus being so small, it has been neglected 

 in the estimations, 



" The Ccirbon computed by the foregoing formula, deducted from the 

 total amount, afforded a basis for calculating the starch, and as the 

 numerous experiments of Horsford and Krocker have shown so con- 

 clusively that the amount of starch may be accurately calculated in 

 this way, no doubt can be reasonably felt with regard to the justice 

 of so doing. Hydrogen and oxygen are accordingly distributed to 

 the carbon, according to the formula 0,2 H,o Oiq. This being done, 

 a balance of hydrogen remained in every case. It was conceived 

 that this was probably due to the fact that the starches cannot be de- 

 prived of all their moisture at 100° C. ; part is also probably owing to 

 moisture absorbed by the starch whilst weighing, as starch dried at 

 100° C. is exceedingly hygroscopic, " taking up in a few days ex- 

 posed to the air 35 per cent, of moisture." (Knapp.) This hydrogen 

 was therefore supplied with oxygen according to the formula of water. 

 It will be seen by consulting the results, that the amount of moisture 

 thus obtained is often quite large, and has a very considerable effect 

 upon the averages. It is on this account, perhaps, somewhat to be re- 

 gretted that the moisture was not determined at 120° or 125° C, in- 

 stead of 100° C. 



" No. I. Corn-Starch, No. 1. 



" Corn-starch is prepared from maize or Indian corn, by the aid 

 either of the ordinary method of steeping and fermenting, or else by 

 steeping the corn, both before and after grinding, in a caustic or car- 

 bonated alkaline lye, the gluten remaining dissolved in the lye. This 

 specimen was in the state of fine powder. 



I. 0.869 grm. gave at 100° C. 0.1392 grm. loss. 

 II. 1.127 grm. dried at 100° C. left 0.0038 grm. ash. 



III. 4.0347 grm. dried at 100° C. left 0.0133 grm. ash. 



IV. 0.3124 grm. gave 0.5017 grm. CO^ and 0.1857 grm. HO. 



