168 MESSRS. RANSOME AND VERNON ON THE INFLUENCE 



remains low (still diminishing as tlie temperature falls 

 until January gth), and it does not again rise until May 

 22nd, 18^8. 



In the two weeks preceding May 22nd 1858, the tem- 

 perature is below the average as much as 6"^ but it now 

 begins rapidly to rise, and from May 2gt]i to June 26th, 

 18^8, it is considerably above the average (on June ^th, 

 nearly 10°).° 



In accordance with the rise of the temperature curve 

 the number of cases increases, and continues to increase 

 steadily, as in the preceding year, until July loth^ when it 

 is 1,200 (on July 1st 1857 it was 1,400), 



But a remarkable difference between the two years must 

 now be noticed, as it aiFords a striking illustration of 

 proposition [b). 



In 1857 the disease runs on after July 11th to an 

 amazing prevalence, but in the present year (1858) there 

 seems to be a sudden arrest, the number of cases remains 

 almost stationary for a fortnight, and then slightly dimi- 

 nishes until August jth. When we inquire into the causes 

 of this difference, we find that whereas in 18^7, from June 

 2o^Ato September 26th, the mean temperature never sinks 

 below 60°; in 1858, for the first two weeks in July, the 

 mean temperature is below 60°; and on July 10th nearly 

 6° below the average. It seems as if the germs of the 

 disease were so far destroyed by the unusual cold, that 

 even the moderate warmth that follows could not again 

 rouse them into activity. 



The mean temperature in 18^8 does not remain above 

 the average, as it did in the preceding year. 



From August yth to August 28^^ 18^8, the diarrhcea 

 curve rises and falls with the mean temperature, but on 

 August 2^th the thermometer again sinks below 60°; and 

 although it again rises in September to 63*5°, it is accom- 

 panied by no corresponding increase in the number of 



