Dr. Waller on the Origin of Mucus and Pus-globules. 403 



completely transparent. After prolonged irritation, however, 

 as in the above-mentioned experiments, when corpuscles are 

 seen diffused over the tongue, such is no longer the case; and 

 numerous corpuscles are then found in the mucus which ex- 

 ists there, and which then possesses all the characters of the 

 substances which are thrown off from the irritated mucous 

 membranes of the human subject. It would be unnecessary 

 to adduce any further evidence of the common origin of these 

 two kinds of mucus, or rather of the globules which they con- 

 tain. 



Purulent matter. — Although the formation of purulent mat- 

 ter itself has not been included in the present observations, 

 (this subject requiring a separate examination, which I will 

 defer to a future occasion,) the presence of its most general 

 and constant ingredients, viz. the purulent globules and the 

 fibro-albuminous fluid which contains them, may easily be 

 explained by the preceding observations, in which the extra 

 fibrillation, corpusculation, and the extra corpusculation of 

 the vessels, represent on a small scale all the principal phe- 

 nomena accompanying its formation. 



Absorption. — After having shown the manner in which the 

 capillaries, engorged with stagnant blood, give off the cor- 

 puscles which they contain, it now remains to examine how 

 they are enabled to discharge the rest of their contents. When 

 these contents consist of blood in a fluid state, we can readily 

 understand how, after the removal of the irritation, the en- 

 gorgement would gradually cease, as is constantly observed with 

 regard to vessels in this state. But many of these vessels, 

 particularly those which have given off corpuscles, contain 

 blood which appears to consist of a gelatinous mass, and is 

 probably in a state of coagulation. The most simple notion 

 of hydrodynamics shows the difficulty of driving a material of 

 a semi-solid consistency through a delicate elastic tube. The 

 question then arises as to the process by which these vessels 

 discharge their contents and become again capable of con- 

 veying the blood to the parts which depend upon them for 

 their nutrition. The following observations will in a great 

 measure answer this question. 



The frog of Obs. 1, after being kept twenty-four hours in 

 water, was examined. The tongue, at first of its natural co- 

 lour, became gradually injected, and presented the same ap- 

 pearances as were observed on the preceding day, with respect 

 to the circulation and the escape of the corpuscles from the 

 vessels. But in addition tubes were perceived in numerous 

 places, containing an amorphous, colourless and nearly trans- 

 parent substance, incompletely rilling the cylindrical cavity 



2 E2 



