July 15,1925 Effect of Dehydration upon Bacterial Flora of Eggs 
159 
All counts were made on the gram basis of the liquid product. 
For the liquid egg, the sample was weighed in a glass-stoppered flask, 
on an analytical balance, to the nearest one-hundredth ol a gram, and 
nine times that weight of physiological salt solution (considering that 
1 c. c. is equal to 1 gmj was added. This was called the 1 : 10 
dilution. Sterile glass beads were added to help break up the egg. 
In the analyses of the dried product, salt solution was added to give 
approximately the same percentage of total solids as in the 1 : 10 
dilution of the liquid product. This was taken as the 1:10 dilution 
of the dried product. By this procedure the counts of the dry prod¬ 
uct were comparable with those of the liquid product. 
There was some difficulty in obtaining solutions of the dried 
product. Apparently the powder did not go completely into solution, 
but was broken up very finely to form a suspension, so that the product 
could be regarded as in solution only when no large undissolved 
particles were present. 
The results in Table I show that there is a big reduction in the total 
number of viable bacteria, and in some cases a complete loss of the 
colon-aerogenes group, during the drying process. 
In addition to the total bacteria counted, a large number of organ¬ 
isms were isolated from the spray-process samples. Some of these 
organisms of general types, as those of the colon group and a few of the 
aerobic spore-formers, were identified, but most of them could not be 
identified absolutely. Organisms of the colon type were predominant 
in the liquid product, and organisms of the aerogenes type were 
predominant in the dried products. This change in the types might 
be explained either by a difference in the heat resistance of the two 
types, or by a greater sensitiveness of the colon type to the change in 
pressure involved in the spray process. Further experiments have 
not been carried out to prove which of the two hypotheses is correct. 
VACUUM-DRUM PROCESS 
GENERAL PROCEDURE 
Experiments in drying eggs by the vacuum-drum method were 
undertaken in the summer of 1923. Chemical and bacteriological 
analyses were made on the liquid and dried products, and the odor 
before and after drying was noted. The plan of the work was similar 
to that followed in the spray process. 
The eggs were broken and dried as in the spray process, and mixed 
by hand with a perforated disk. Two cases were broken each day. 
The first case was dried approximately 2 hours after breaking. The 
second was held in an ice box, and dried approximately 5 hours 
after breaking. The temperature of the drum was usually about 90° 
C., but a few of the samples were dried at 88°, and a few at 93°. 
The exposure was 15 to 20 seconds. 
GRADES OF EGGS USED 
A few eggs of each grade were candled before the experiments 
were started. Inspection of the eggs at the breaking table, how¬ 
ever, was taken as the best way of ascertaining the quality. Three 
grades were used—commercial firsts, heated, rots and spots. In 
general, the commercial firsts proved to be of very good quality. 
A few showed a little heat. The heated eggs were uniformly of 
