CHAPTER XIII. 



CONTAINING SOME PATHOLOGICAL OBSERVATIONS RELATING TO 

 THE LYMPHATIC SYSTEM. 



THE fluids which lubricate the different cavities of the body 

 are sometimes collected in these cavities in an extraordinary 

 quantity, and form dropsies, such as the ascites, anasarca, 

 dropsy of the pericardium, thorax, tunica vaginalis, &c. 



In a former chapter we observed, when speaking of the 

 lymph that moistens such cavities, that its properties vary in 

 different circumstances; that in these dropsies the fluid that 

 is let out by tapping is generally as thin as water, and in- 

 stead of coagulating, when exposed to heat, only becomes a 

 little turbid. Sometimes indeed it agrees with the serum of 

 the blood in coagulating by heat, and sometimes it flows from 

 these cavities in a viscid or ropy state. In all these cases the 

 fluid occasioning the dropsy is different from the fluid that 

 naturally moistens those cavities, which, in experiments related 

 above, was found to agree with the coagulable lymph of the 

 blood, in the circumstance of jellying merely by exposition to 

 the air. 1 



These circumstances being considered, I think we may 



1 The water in the ventricles of the brain should, I believe, be excepted, as I 

 never saw it jelly, even when exposed to heat (LXXXIX). 



(LXXXIX.) The fluid of a blister, when let out and set aside, fre- 

 quently coagulates spontaneously : see the careful observations by Dr. 

 A. Buchanan, in the ' Proceedings of the Philosophical Society of Glas- 

 gow/ No. 7 ; and note to the English edition of Gerber's 'Anatomy/ 

 p. 105. As observed in Notes LXVIII and LXIX, the fluid of the lym- 

 phatic vessels and of the pericardium does not always coagulate sponta- 

 neously when taken from healthy animals. The effect of heat on some 

 fluid from the vaginal tunic of the testicle is mentioned in Note xvn j 

 and the coagulation of that fluid, at the temperature of the air, when 

 mixed with serum of blood or with some other substances, in Note xviu, 

 p. 31. 



