XL A^jpendix. 



and that wlien 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 ail 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 during 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 



