d\6 PHILOSOPHICAL TRANSACTIONS. [aNNO 1755. 



ficient information to be convinced within himself, he should not be wanting to 

 communicate what might tend to advance this branch of natural knowledge, and 

 to promote a true theory of diseases, on which all rational practice must be 

 established. 



XXXIX. Of Worms in Jnimnl Bodies. By Frank NichoUs, M. D. Med. Reg. 



and F. R. S. p. 246. 



Fish are, to appearance, more subject to worms* than other animals; the cod 

 often shows small slender worms, coiled up like snakes, on the surface of its 

 liver; and the bley in the Thames, about the month of July, is often distressed 

 by a long flat worm, which, by possessing and eating its liver, prevents the fish 

 from compressing itself to that specific gravity, which is necessary for its quiet 

 continuance under the water; so that it is obliged to skip about on the surface of 

 the water, till it becomes a prey to its foes, or dies suffocated, by being so often 

 out of water, and deprived of that action of the water which is analogous to the 

 force of the air to us in breathing. 



Among the many cases, which Dr. N. had seen, two seem to deserve parti- 

 cular attention, as well because they are greatly prejudicial to the farmej, as be- 

 cause, when generally known, they may possibly lead to a method of successful 

 cure. The first of these is a species of dropsy, incident to bullocks and sheep. 

 On opening these animals, when dead of this rot, the liver is always found affected. 

 A small fiat worm,-|- resembling a sole, and often many of them, is found in 

 the gall-duct, by the butchers termed fiooks [flukes]. It is the property of this 

 worm, that it always builds a wall of stone for its defence; which wall is ramified 

 like the gall-duct, within which it is formed. This stony tube, when completed, 

 blocks up the gall-duct, and stops the passage of the gall ; which thereby sur- 

 charging the duct, and dilating the orifice of the lymphatics, returns again into 

 the blood, and gives the yellow teint to the eyes, which is the first symptom of 

 this disease, and generally precedes the loss of flesh, and the swelling of the 

 belly. It seems probable, that whatever can increase the acrimony of the bile, 

 must be useful in preventing this disease; but when the stony pipe is formed, no 

 method seems capable of promoting its discharge, or dissolution. 



The other case is termed the husk, and is a disease to which bullocks are very 

 subject, while young; for it rarely afTects those of more than a year old. The 

 creature is seized with a short dry cough, by which it is perpetually teized ; in 

 consequence of which he wastes in flesh, and grows weaker and weaker till he 

 dies. On opening the lungs of a calf dead of this distemper, he found the wind- 



* The worm here alluded to, is the ligula abdomiiialis. Linn. Goiel. 

 + This worm is thefoiciola hepatica. Linn. 



