<30 NARRATIVR OF A JOURNEY 



tries, pierce the fl:in, and depolit thier ova, which pro- 

 dude the worms in queftion. 



Without pretench'ng todecide between the t^^/o fup- 

 politions ; or adverting to the difficulty of conceiving- 

 how the ova could preferve their vivifying princifile, 

 through the procefles of digcftion, chiliflicl:ion, and cir- 

 culation, till they are finally depofited, by the capillary 

 arteries, in the cellular texture; the obferration th:}r 

 thefeinfedls are only found in the extreuuties, and moll 

 frequently in the lower, which are mofl expofed to im- 

 merfioninllagnant water, pleads itrongly intavour of the 

 third hypothefis. The following fa<5l renders it proba- 

 ble, tliatthe generation and the growth of theworm.after 

 the ova iiave been depolitcd, is very flow. Ahhoucb. 

 thecomplaint was very frequent among the inhtlbi^'">nts 

 of Oujein, our people remained exempt from it, durip.g 

 our refidencc there, for eleven months; but in the 

 month of Augnjl following (five months after we left 

 tlie place) the difeafe broke out in many. In all the 

 cafes which fell under my obfervation, the worm was 

 lodged in the lower extremity, excepting one inftance. 

 This patient, who was a bhiihtee, or water-man, had 

 the complaint break out in his arm. The nature of his 

 profefiion expofed his arms, more than thole of other 

 people, to the attacks of the parent infedl: fuppoling 

 her to relide in the water.* 



* Dr. CaisnoLM afcribes the difeafe, which is very prevalent 

 among the negroes in Grenada, to their drinking the water of cer- 

 tain wells, in uhich the naked eye diftinguifties innunerable ani- 

 malcules. On one ellate, where no other water can be had, they 

 are attacked regularly every year, about the month of Novembt-r-, 

 in the month of January, the difeafe fpreads through the greateft 

 part of the gang; and in the month of March, it entirely difap- 

 pears, till the following November. On other cltates, the difeafe 

 was equally frequent, till the obnoxious wells were filled up, ciflerns 

 built, or were dug in places not fubjeft to the influence of the ebb 

 and flow, of the tide ; at the return of the ufual period of the ap- 

 pearance of the GuhiL-a worm, nothing of the kind happened. I'his 

 is a ltrongpro(jf that the infeii which produces the worm relkles in 

 the water, but it is equally reconciliable to the fuppofition that the 

 ova are depofited under the fkin, when any part of the externnl fur- 

 face is itr.mergcd in the water, as that of their propagating after 

 being fwaliowed suih llie drixik. As svc know tliat molt infefts 



have 



