DISEASES CLASS II. 1.3. 



By certain animal motions of the terminations of the vefTels, 

 Hence a new kind of gland is formed at the terminations of the 

 reffels in the eruptions of the fmall-pox j the animal motions of 

 which produce from the blood variolous matter ; as other glands 

 produce bile or faliva. Now if fome of this matter is introdu- 

 ced beneath the cuticle of a healthy perfon, or enters the circula- 

 tion, and excites the extremities of the blood-veffels into thofe 

 kinds of difeafed motions, by which it was itfelf produced, either 

 by irritation or affociation, thefe difeafed motions of the extremi- 

 ties of the veffels will produce other fimilar contagious matter. 

 See Sect. XXXIII. 2. 5. and 9. Hence contagion feems to be 

 propagated two ways ; one, by the ftimul us of contagious mat- 

 ter applied to the part, which by an unknown law of nature ex- 

 cites the ftimulated veffels to produce a fimilar matter ; as in 

 venereal ulcers, which thus continue to fpread ; or as when va- 

 riolous matter is inferted beneath the cuticle ; or when it is 

 fuppofed to be abforbed, and diffufed over the body mixed with 

 the blood, and applied in that manner to the cutaneous glands. 

 The other way, by which contagion feems to be diffufed, is by 

 fome diilant parts fympathizing or imitating the motions of the 

 part firft affected j as the ftomach and fkin in the eruptions of 

 the inoculated fmall-pox, or in the bite of a mad dog ; as treat- 

 ed of in Sea. XXII. 3. 3. 



In fome of the difeafes of this genus, the pulfe is Itrong, full, 

 and hard, conftituting the fenfitive irritated fever, as defcribed 

 in the preceding genus ; as in one kind of eryfipelas, which re- 

 quires repeated venefection. In others the arterial action is 

 fometimes moderate, fo as to conftitute the fenfitive fever, as in 

 the inoculated fmall-pox ; where the action of the arteries is 

 neither increafed by the fenforial power of irritation, as in the 

 fenfitive irritated fever j nor decreased by the defect of that pow- 

 er, as in the fenfitive inirritated fever. But in the greateft num- 

 ber of the difeafes of this genus the arterial action is greatly di- 

 minilhed in refpect to ftrength, and confequently the frequen- 

 cy of pulfation is proportionally increafed, as explained in Sect. 

 XXX1L 2, i. Which is owing to the deficiency of the fenfo- 

 rial pov/er of irritation joined with the increafe of tnat of fenfa- 

 tion, and thus constitutes the fenfitive inirritated fever > as in, 

 fcarlatina with gangrenous tonfils. 



From this great debility of the action of the arteries, there 

 appears to be lefs of the coagulable lymph or mucus fecreted on 

 their internal furfaces ; whence there is not only a defect of 

 that buff or fize upon the blood, which is feen on the furface of 

 that which is drawn in the fenfitive irritated fever ; but the 

 blood, as it cools, when it has been drawn into a bafm, fcarcely 



coagulates j 



