Upon the subject of turning eggs the writer will admit that he is doing what poultry writers as a class do on a great many occasions, i.e.:  expressing an opinion rather than giving the proven facts.  In incubation practice it is highly desirable to change the position of eggs so that unevenness in temperature and evaporation will be balanced.  When doing this it is easier to turn the eggs than not to turn them, and for this reason the writer has never gone to the trouble of thoroughly investigating the matter.  But it has been abundantly proven that any particular pains in egg turning is a waste of time.

Cooling Eggs.

The belief in the necessity of cooling eggs undoubtedly arose from the effort to follow closely and blindly in the footsteps of the hen.  With this idea in mind the fact that the hen cooled her eggs occasionally led us to discover a theory which proved such cooling to be necessary.  A more reasonable theory is that the hen cools the eggs from necessity, not from choice.  In some species of birds the male relieves the female while the latter goes foraging.

But there is no need to argue the question.  Eggs will hatch if cooled according to custom, but that they will hatch as well or better without the cooling is abundantly proven by the results in Egyptian incubators where no cooling whatever is practiced.

Searching for the “Open Sesame” of Incubation.

The experiment station workers have, the last few years, gone a hunting for the weak spot in artificial incubation.  Some reference to this work has already been made in the sections on moisture and ventilation.  Before leaving the subject I want to refer to two more efforts to find this key to the mystery of incubation and in the one case at least correct an erroneous impression that has been given out.

At the Ontario Station a patent disinfectant wash called “Zenoleum” was incidentally used to deodorize incubators.  Now, for some reason, perhaps due to the belief that white diarrhoea was caused by a germ in the egg, this idea of washing with Zenoleum was conceived to be a possible solution of the incubator problem.  In the numerous experiments at that station in 1907 Zenoleum applied to the machine in various ways was combined with various other incipient panaceas and at the end of the season the results of the various combinations were duly tabulated.  The machine with buttermilk and Zenoleum headed the list for livable chicks.

For reasons explained in the chapter on “Experiment Station Work,” the idea of contrasting the results of one hatch with one sort with the average results of many hatches of another sort is very poor science.  Feeling that the Station men would hardly be guilty of expressing as they did in favor of such a method without better reason, I very carefully went over the results and compared all machines using Zenoleum with all machines without it.  The results in favor of Zenoleum were less marked but still perceptible.