INTEODUCTION. 51 



states of nutrition as to give no tendency to renew it. 

 But while admitting this mode of action of external 

 stimulants, we cannot refuse to admit the derivative effect 



of COUNTER-IEEITANTS. 



Kecent researches on the vaso-motor system have 

 proved how powerful an effect a stimulus may have in 

 altering blood- distribution. These researches, though by 

 no means complete, are favorable to the view that a 

 deep-seated inflammation may be relieved by originating 

 a similar process in superficial tissues. Setons, blisters, 

 cauteries, and rubefacients are means to this end. 



Cold, when applied locally in a continuous manner for 

 a long time, will, in such cases as open joints and similar 

 pathological states, enable repair to occur with a minimum 

 of inflammation, for such, if it set in to a marked degree, 

 would cause high fever on account of the unyielding nature 

 of surrounding parts. Also under this treatment the in- 

 flammation is not so liable to involve the joint surfaces. 

 This continuous application numbs the parts, and so lessens 

 pain ; but some say that ultimately the white muscular 

 fibre of the arteries relaxes, and passive congestion occurs. 

 However this may be, its practical value in joint diseases 

 has been proved. 



Heat with Moistuee relaxes parts, and so eases pain, it 

 also tends to promote suppuration. It must be used, 

 therefore, to assist the maturation of abscesses, but should 

 be avoided whenever suppuration would be prejudicial. In 

 the earliest stages of inflammation resolution may be 

 brought about by warmth, mechanically relaxing the 

 vessels in which stasis has occurred, and thus readmitting 

 the current of blood, or the same effect may be the result 

 of extravasation. 



Local Sedatives, as Goulard's solution of the subacetate 

 of lead, check the spread of inflammation by lessening the 

 passive congestion around the seat of stasis ; they are very 

 useful in cases of ophthalmia, contusions, &c. 



Local Blood-letting must never be brought about by 

 incisions in the inflamed part, but rather in the proximity. 

 It seems to temporarily relieve congestion and hyperaemia^ 



