374 ESSAYS and OBSERVATIONS 



infedion fpread no further, not even fo much 

 as to one in the fame houfe. 



III. The fubied;s which were fufceptible 

 of this fever, were both fexes of the white 

 colour, efpecially ftrangers lately arrived 

 from cold climates, Indians^ Mijlees, Mulat- 

 toes of all ages, excepting young children, and 

 of thofe only fuch as had formerly efcaped the 

 infeftion. And indeed it is a great happi^ 

 nefs that our conftitutions undergo fuch alte- 

 rations in the fmall-pox, meafles and yellow 

 fever, as for ever afterwards fecure us from 

 a fecond attack of thofe difeafes. There is 

 fomething very fingular in the conftitution 

 of the Negroes, which renders them not 

 liable to this fever j for tho' many of thefe 

 were as much expofed as the nurfes to the 

 jnfedion, yet I never knew one inftance of 

 this fever amongft them, tho' they are e- 

 qually fubjed; with the white people to the 

 bilious fe'uer. 



IV. This fever began in the middle or 

 rather towards the end of Aiigii-Ji, and con- 

 tinued till near the middle of OSiober^ when 

 the weather became cold enough to prevent 

 its 'further progrefs. In the beginning of 

 Augiifi:, the weather was warmer than I had 



ever 



