CANDLING EGGS 463 
that a product prepared even from spots and worse, might satisfy the 
ordinary bacterial tests if stored for a period of a few months. 
Frozen Eggs. Stiles and Bates (1912) prepared frozen eggs in the 
laboratory from second-grade eggs. Such a product had generally a 
bacterial content of 1,000,000 per gram. Frozen eggs prepared from 
spots, rots and blood rings gave a bacterial content of from 4,000,000 to 
1,000,000,000 per gram with a relatively high content of B. colz and 
streptococcus. Pennington (1916) reported a careful study of this sub- 
ject and pointed out many features in the sanitary control of the in- 
dustry. 
Candling of Eggs. The control of the commercial egg industry by 
chemical or bacterial analyses is very impracticable. Pennington (1909) 
has pointed out that each egg is a package by itself and an analysis of 
it would in no way indicate the condition of the lot. This has made 
it necessary for those engaged in food control to look for other methods 
for determining the fitness of eggs for consumption. Candling has 
developed to satisfy this need. Frazier (1917) states that this consists 
in ascertaining the character of an egg by allowing light to penetrate 
the contents. Different contrivances are used to do this. An electric 
light yields the most satisfactory results since it is constant in inten- 
sity and quality. Many cheap types of candling devices are used. 
Benjamin has described two common types. These are shown in 
Fig. 77. The accurate use of the candlng apparatus demands some 
experience before reliable results may be obtained. The colored plates 
will be of much assistance. They are taken by permission from the 
bulletin by Professor Benjamin. Pennington et al. (1918) have recently 
published instructions for candling eggs. Those wishing a complete 
classified description of eggs before the candle and outside of the shell 
will be rewarded by reading this bulletin. 
Bacterial Examination of Eggs. Much discussion has passed back 
and forth over the methods of egg analysis. The early methods were 
probably faulty as Hadley has said and data from the earlier work must 
be accepted with some reservation. Hadley has discussed the methods 
of analysis and any one interested in that subject should consult his 
work. 
Stiles’ Method. The eggs should be washed in a solution of bi- 
chloride of mercury (1/1000) or 5 per cent phenol for a few minutes 
after which they should be dried with sterile cotton and placed with 
the large end uppermost in a small beaker. The air space is then 
scorched with a gas flame for a few seconds. An opening should be 
made immediately into the cavity with sterile forceps, a sufficient 
