XL Appendix. 
and that when the predisposition is once developed, the high temperature of 
a single day acts as an exciting cause, or at least as an aggravating influence.” 
He also adds, “ Reasoning from these facts alone, we must not conclude 
that the predisposition induced by hot weather is a mere debility, since if 
such were the case we should find the greatest mortality towards the end of 
the hot weather, when this debility is the greatest in degree, and most 
extensively prevalent ; which is not the fact, the records showing a steady 
decrease in the daily list of deaths, even though the temperature should 
remain above ninety degrees. Looking at all the facts, is it illogical to infer 
that cholera infantum requires for its development generally a certain occult 
condition of the system, which, when acted upon by a certain atmospheric 
temperature continued for a longer or shorter period, induces a predisposition 
to the disease ; and that children who are not previously in this occult state 
are not liable to the disease at all, no matter what the temperature and its 
resulting debility might be?” 
These remarks coincide with what I have stated as obtaining in all 
epidemics. In order to obtain some idea as to what the occult state may be, 
we ask the following question: At what ages are infants most liable to these 
disorders? The general idea is that the process of dentition has much to do 
with these affections, and teething time is looked upon by the public at large 
with anxiety as the period of infant life most fraught with danger. 
The following statement of the ages at which the 103 deaths from 
intestinal disorders took place, leads to a rather different conclusion -—Out 
of the 103 deaths, two occurred during the first month, five during the second 
month, ten dering the third month, nine during the fourth month, thirteen 
during the fifth month, eleven during the sixth month, eleven during the 
seventh month, fifteen during the eighth month, two during the ninth month, 
three during the tenth month, eight during the eleventh month, and four 
during the twelfth month. Ten deaths took place during the second year, 
and one just over two years old. Seventy-five deaths out of the 103 occurred 
during the first eight months, and the eighth month was the most prominently 
fatal. 
Dr. Dudley arrives at somewhat ‘similar results from the records of a 
much greater number. Out of 4,013 deaths that took place in Philadelphia 
in children under two years of age, during a period of five years, from cholera 
infantum, he found that 2,073, or more than half, perished before the end of 
the eighth month, and three-fourths of the number perished before the end 
of the first year. He found the fifth and the seventh months to be the most 
prominently fatal of all. 
_ The process of dentition, beginning at the seventh or eighth month, is not 
completed until the twenty-fourth or thirtieth. It therefore follows that this 
