INTESTINAL WORMS. 237 



acidulous water of this kind had been drank with 

 the design of expeUing these worms.* This 

 account, however, proves too httle; for, as Bonnet, 

 Rvaumur, Pallas, and other eminent naturalists 

 remark, if such were the fact, we siiould find in- 

 testinal 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 Lin- 

 naeus 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 cotnmon small thread worm (Oxyuns 

 vermicidaris, Brf.mser) in the water of a well — the 

 aquatic only ditfering from the intestinal worms 

 in colour. But were all descriptions as loose as this 

 the gro.'^sest mistakes must ensue; for it is quite 

 clear that Dr Barry's aquatic worms were a very 

 common species (JVais), and though similar in 

 external form, altogether different in internal 

 structure from the Oxijuridce 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 empire; since there 

 are few individuals who are not aflected with these 

 worms at some period of their lives. According to 

 our experiments, the nais ceases to exist in a tem- 

 perature considerably less than that of the human bo- 

 dy; besides, as it lives on minute fresh-water mollus- 

 ctv, it could find no food in tlie intestines.! 



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;'J for, if so, the 



* Linnfeus, quoted by Bonnet, CEuvres, iii, 1.37. t J. R. 



4: Frank. De Curand. Homin. Morb. lib. vi. 



