INTESTINAL WORMS. 237 



acidulous water of this kind had been drunk with the 

 design of expelling these worms.* This account, 

 however, proves too little ; for, as Bonnet, Reaumur, 

 Pallas, and other eminent naturalists remark, if such 

 were the fact, we should find intestinal worms (so 

 very numerous in most animals) swarming in such 

 places, and from their size (Boerhaave saw one thirty 

 ells long) they could not escape observation ; whereas 

 this was at that time the only instance recorded of 

 one found out of the body. We are of opinion that 

 Linnaeus must have been deceived by similarity of 

 form. A subsequent instance is recorded by Dr. 

 Barry, of Cork, who imagined he had found the 

 origin of the common small thread-worm {Oxyuris 

 vermicularis, Bremser) in the water of a well — the 

 aquatic only differing from the intestinal worms in 

 colour. But were all descriptions as loose as this 

 the grossest mistakes must ensue ; for it is quite clear 

 that Dr. Barry's aquatic worms were a very common 

 species (Nais), and though similar in external form, 

 altogether different in internal structure from the 

 OxyuridcE of the intestines. Were the latter, indeed, 

 introduced into the body from water, they would not 

 only be found in this particular well, two miles from 

 Cork, but would swarm in all the waters in the em- 

 pire ; since there are few individuals who are not 

 affected with these worms at some period of their 

 lives. According to our experiments, the nais ceases 

 to exist in a temperature considerably less than that 

 of the human body; besides, as it lives on minute 

 fresh-water moUuscse, it could find no food in the 

 intestines, t 



The celebrated Dr. J. P. Frank is no less mistaken 

 in referring us for the origin of intestinal worms to 

 " minute insects flying in the air;"]: for, if so, the 



* Linnaeus, quoted by Bonnet, CEuvres, iii. 137. f J. R. 

 t Frank. De Curand. Homin. Morb. lib. vi. 



