3 7 o DISEASES Class IV. i. i. 3, 



of the ftomach is increafed by direct fympathy with that of the 

 {kin ; and the tendency to vomit, which was owing to its di- 

 minifhed action, ceafes. 



3. Cejfatio agritudinis cute excitatd. The cure of ficknefs by 

 ftimulating the (kin. This is explained in the preceding arti- 

 cle *, and further noticed in IV. 2. 2. 4. and in IV. 1. 1. F. 



Similar to thefe is the effect of a blifter on the back in reliev- 

 ing ficknefs, indigeftion, and heart-burn ; and, on the contrary, 

 by thefe fymptoms being frequently induced by coldnefs of the 

 extremities. The blifter ftimulates the cutaneous veffels into 

 greater action ; whence warmth and pain are produced at the 

 fame time, and the fibres of the ftomach are excited into greater 

 action by their affociation with thofe of the fkin. It does not 

 appear, that the concommitant pain of the blifter caufes the in- 

 creafed energy of the ftomach, becaufe the motions of it are not 

 greater than natural ; though it is fometimes difficult to deter- 

 mine, whether the primary part of fome afibciated trains be 

 connected with irritative or fenfitive motions. 



In the fame manner a flannel fhirt, to one who has not been 

 in the habit of wearing one, ftimulates the fkin by its points, 

 and thus flops vomiting in fome cafes ; and is particularly effi- 

 cacious in checking fome chronical diarrhoeas, which are not at- 

 tended with fever ; for the abforbents of the fkin are thus ftim- 

 ulated into greater action, with which thofe of the inteftines 

 confent by direct fympathy. 



This effect cannot be afcribed to the warmth alone of the 

 flannel {hirt, as being a covering of loofe texture, and confining 

 air in its pores, like a fponge, which air is known to be a bad 

 conductor of heat, fince in that cafe its ufe mould be equally 

 efficacious, if it were worn over a linen {hirt ; and an increafed 

 warmth of the room of the patient would be equally ferviceable. 



4. Digeflio aucla frigore cutaneo. Digeftion increafed by cold- 

 nefs of the fkin. Every one has experienced the increafe of 

 his appetite after walking in the cool air in frofty days ; for 

 there is at this time not only a faving of fenforial power by the 

 lefs exertion of the cutaneous veffels ; but, as thefe confent with 

 thofe of the ftomach and bowels, this faving of fenforial power 

 is transferred by reverfe fympathy from the cutaneous capilla- 

 ries and abforbents to thofe of the ftomach and inteftines. 



Hence weak people fhould ufe the cold air of winter as a cold 

 bath j that is, they fhould ftay in it but a fhort time at once, 

 but fhould immerfe themfelves in it many times a day. 



5. Cat arr hits a frigore cutaneo. Catarrh from cold fkin. This 

 has been already explained in Clafs I. 1. 2. 7. and is further 

 defcribed in Sect. XXXV. 1.3. In this difeafe the veflels of 



the 



