366 PATHOGENIC BACTERIA IN MILK 



mometer has attained somewhere about 56° F., no matter what 

 may have been the temperature previously attained by the atmos- 

 phere or recorded by the one-foot earth thermometer. The 

 maximum diarrhoeal mortaHty of the year is usually observed in 

 the week in which the temperature recorded by the four-foot earth 

 thermometer attains its mean weekly maximum. The decline of 

 the diarrhoeal mortality is in this connection not less instructive, 

 perhaps more so, than its rise. It coincides with the decline of the 

 temperature recorded by the four-foot earth thermometer, which 

 temperature declines very much more slowly than the atmospheric 

 temperature, or than that recorded by the one-foot thermometer ; 

 so that the epidemic mortality may continue (although declining) 

 long after the last-mentioned temperatures have fallen greatly, and 

 may extend some way into the fourth quarter of the year. The 

 atmospheric temperature and the temperature of the more super- 

 ficial layers of the earth, is little if at all apparent until the 

 temperature recorded by the four-foot earth thermometer has risen 

 as stated above ; then their influence is apparent but it is a sub- 

 sidiary one." 



In addition to these conditions of soil, Ballard and other 

 workers have concluded that insanitation in the widest sense of 

 the term favours epidemic diarrhoea. Density of population, or 

 houses, upon an area, unclean soil, dusty surfaces, bad light, 

 absence of ventilation, maternal neglect, etc., all have a share 

 in creating an environment favourable to the disease. As we 

 have seen, Delepine, like Ballard, attributes the disease in large 

 measure to milk. Ballard believed that milk gained its infec- 

 tion by unsuitable storage and by the mode in which it was 

 used. He found that " infants fed solely from the breast are 

 remarkably exempt from fatal diarrhoea ; that infants fed in 

 whatever way with artificial food to the exclusion of breast milk 

 are those which suffer most heavily from fatal diarrhoea ; that 

 children fed partially at the breast and partially with other kinds 

 of food, suffer to a considerable extent from fatal diarrhoea, but 

 very much less than those brought up altogether by hand ; and 

 that, as respects the use of ' the bottle,' it is decidedly more danger- 

 ous than artificial feeding without the use of the bottle." 



Dr Newsholme of Brighton, has published an interesting paper 

 on the causation of epidemic diarrhoea. Some of his chief con- 

 clusions, which are now widely accepted, may be added : — 



"(i) Epidemic diarrhoea is chiefly a disease of urban life. 

 (2) Epidemic diarrhoea as a fatal disease, is a disease of the artisan 

 and still more of the lower labouring classes to a preponderant 



