60 BULLETIN 846, U. S. DEPARTMENT OF AGRICULTURE. 
INTERPRETATION OF RESULTS OF INVESTIGATION. . 
A series of plots (figs. 1, 2, 3, 4, and 5) was made, with the purpose 
of finally grouping into a single expression the information obtained. 
AMMONIA NITROGEN. 
On cross-section paper the amounts of ammonia nitrogen, expressed 
as milligrams per 100 grams of sample on the wet basis, were plotted 
as ordinates against the percentages of ether extract as abscissas. The 
percentages of ether extract as abscissas were chosen not because the 
ether extract is destroyed by bacterial or enzymatic action in direct 
proportion as the ammonia increases, but because the normal amount 
of ammonia was found to be greater in yolk than in whole egg, even 
when prepared from the freshest eggs obtainable. It is also a known 
_ fact that practically all of the ammonia nitrogen occurs in the yolk 
and that there is no appreciable increase of ammonia nitrogen in the 
whites of storage eggs or in decaying liquid whites. Therefore any 
increase in ammonia nitrogen in whole egg is due to decomposition 
of the yolk, of which the white acts practically as a diluent. Because 
the ether extract is the best available measure of the amount of yolk 
present, it was used as the abscissa. Moreover, there is a very great 
tendency at present to make yolky mixtures, which theoretically 
may be judged as to quality, as far as ammonia is concerned, if a 
curve can be drawn, one end of which is determined by the results 
found for white and the other end for yolk, and which will pass at an 
intermediate point through the results for whole egg. 
The increased amounts of yolky mixture now made are largely 
due to the demand at present for much more yolk than white. If 
no preventive steps were taken, white would become a drug on the 
market. Consequently, in making contracts, especially in the pro- 
ducing section, many breakers demand that the bakers shall take 
equivalent amounts of yolk and white. As this would provide the 
bakers with more white than they need if they based orders on their 
requirements for yolk, they overcome the difficulty by ordering what 
white they need and then arranging that the equivalent amount of 
yolk shall be mixed with enough whole egg to give them an amount of 
yolky mixture equal to the necessary amount of yolk. They can not 
entirely substitute yolky mixture for yolk, but they can do so toa 
very large extent, if they are careful not to have so much whole egg 
in the mixture that their baking recipes are upset. Obviously, in 
fillmg one contract, the amount of yolk in the yolky mixtures may be 
high, while in another it may be low, with the possibility of all de- 
grees of intermediate mixtures. The amount of whole egg in the 
mixture has been observed to increase as the season advances. To 
judge such mixtures fairly it has been proposed that the ammonia 
