REPORT OF THE CHEMIST. 155 
common starch too high, through having calculated all of the albumin- 
oids except zein as being soluble in water. 
A very noticeable fact is that the microscope shows the starch gran- 
ules of sweet corn to be very much larger (.001 inch diameter) than those 
in ordinary corn (in White Dent .66025 to .0003 inch diameter, T. Taylor). 
If a whole grain of sweet corn be soaked in water containing a Little 
acetic acid there will be extracted the same soluble starch which was ob- 
tained in analysis of the powdered grain. This starch shows no organ- 
ized granular structure when seen under the microscope, and when 
treated with iodine the liquid appears equally colored throughout. 
From this it appears that there exists in sweet corn a cousiderable 
amount of strach in an amorphous and soluble condition. That this 
amount may be slightly increased by the process ot pulverization in an 
iron mortar is possible, for it has been shown by Redwood that large 
starch-grains may be ruptured by trituration, while smaller grains es- 
' Cape. 
The considerable variations in the amounts of soluble starch and gum 
in the different sampies of sweet corn may be due to various causes. 
First. Ditferent amounts actually present. 
Secondly. A greater number of stareh-grains may be ruptured in pul- 
verizing different samples. 
Thirdly. It seems probable that partial seeenieelg of the air-dry 
sample may render part of the stareh soluble. 
It is well known that ordinary cornmeal undergoes some such changes 
when kept for some time, and it would seem that the meal from sweet 
corn, containing, as it does, much more sugar, would be still mere 
likely to ferment. 
It is almost impossible to get identical amounts of water extract from 
the same sample of sweet corn, even when duplicate determinations are 
made at the same time and under the same conditions. It appears, then, 
that the figures for soluble starch are valuable chietly as preliminary 
Statements. Work already commenced will, it is hoped, give more defi- 
nite results and better methods of estimation. 
ESTIMATION OF TOTAL ALBUMINOIDS.—The grass is burned with ex- 
cess of soda-lime, and the evolved ammonia received in decinormal acid. 
The total nitrogen multiplied by 6.25 equals the total albumnioids. 
Sweet corn differs from ordinary field corn in several particulars : 
1. In its greater content of sugars; in the samples analyzed the pro- 
portion is 2.65 to 1. 
2. In sweet corn the amounts of sugar and zein are about equal; in 
field corn the proportion of zein to sugar is 2.7 to 1. 
3. Only 5 to 5.5 per cent. of field corn is dissolved by cold water; the 
solution so formed may be filtered perfectly clear, and contains no star ch, 
but only sugars and gum. If sweet corn be treated in the same way 
with cold water a nilky liquid results which cannot be Lltered clear by 
useof double papers. The amounts thus dissolved average about 32 per 
cent. of the air-dry grain. The filtered solutions thus obtained contain 
some amylaceous matter, which gives with iodine a light violet color; 
when only a slight amount of iodine is added the color fades, but may 
be renewed by further additions of iodine. This amylaceous ‘matter is 
probably similar to the “amiduline” aud “ amylogen” of older German 
chemists. It will be understvod that the term “ soluble starch” is used in 
these analyses to indicate this soluble matter which is colored bine-violet 
by iodine. In this connection it seems probable that the analysis of 
“Stowell’s Evergreen sweet corn,” made by W. O. Atwater,* is, in part, 
ae ee Ss Sk hae 2M) ae Ne ee 
*American Journal Science and Arts, 1869, vol. 43, p. 352. 
