7 RT At ORE Seah Se Oe ie es en 
2 PAF i ey Psy ub Ay Ue ia ae meh Vey “ 
pe Got tes ‘ . ‘ BT 9 aN ee cee 
, hw . “ . ah it 
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‘ 

164° in ! [Asseusny fe: 
tion of this by exhausting with ether, and the remainder of the meal 
returned to the oven where it was left for several days when the fat 
was again determined. ‘This experiment was repeated with the result 
siven below : 
TIME OF DRYING, 30 hours. 1 days. 30 days. 40 days. 
HGher ex trAGbe Leo). ive ws 5.84 5.14 3.45 — ies ay 
Hither. extract, LD recy e soviet. 5.87 mite 3.21 Ls 
This marked decrease is not due to a loss of fat, but to some change 
which renders it insoluble in ether. Fat extracted from corn meal 
becomes practically insoluble in ether RiSGt being dried several days 
at 100° C. 
The dried substance is ground together in a common drug mill, the 
grinding being repeated till the sample is sufficiently fine for the sev- 
eral deter minations, and is preserved in -glass-stoppered bottles until 
wanted for further examination. 
A quantity of this is again dried at 100° C. to remove the moisture 
absorbed while being ground, before taking portions fur the remainder 
of the analysis. 
y 
2 Ash. — 
The ash is determined by burning about five grams of substance in 
a tared platinum dish at low redness. . The burning is greatly facili- | 
tated by suspending a concave piece of platinum foil a short distance y 
above the dish. ‘This foil may be heated by an extra lamp from above, 
if the burning proceeds slowly.. Most substances, however, burn 
readily, to a nearly white ash, without heat from above. The crude | 
ash obtained as above is what is represented in the analyses given in 
this report. 















3. Albuminoids. Total nitrogen. 
The crude. albuminoids, only, obtained by multiplying the total — 
nitrogen by 6.25 are considered in the fodder analyses. 
The total nitrogen has, in all cases, been determined by Varrentrapp 
and Wills’ method. ‘The'soda-lime used has been prepared by heating 
together equal parts of crystalized carbonate. of soda and lime, as — 
described by Prof. Johnson in the Connecticut Station Reports. 
In Fresenius’ Zeitschrift fiir Analytische Chemie, 1883, 3, appeared - 
a new method for the estimation of nitrogen in organic substances by 
J. Kjeldahl. The method consists in treating 0.3 to 0.7 gram of - 
substance, according to the amount of nitrogen that it contains, with — 
10 ¢.c. of concentrated sulphuric acid. The substance is weighed in 
a flask of about 100 c.c. capacity, the acid added and the mixture 
heated to nearly the boiling point of the acid till the substance is dis- 
solved. This seldom takes more than two hours. The substance 
need be pulverized only so far as is necessary for obtaining a good. 
sample. ‘To the solution in sulphuric acid, while still hot, is added — 
gradually dry potassium permanganate in fine powder, till the organic 
matter is completely oxidized. The reaction is very violent, flashes of 
light often appearing in the flask; there is, however, no danger of loss | 
of nitrogen. ‘The liquid becomes first colorless and transparent and 
finally green when-the oxidation is completed. The nitrogen in or- ~ 
