INTEGUMENTS. 



forms the reticular body. On thofe properties depend im- 

 iriediately, I, the capillary circulation ; 2, the cutaneous ex- 

 lifilation ; 3, the abforption ; 4, tlie nutrition of the dermoid 

 fyftem ; aad 5, the fecretion of the cutaneous oil, where fe- 

 baceous glands exid. Befides thcfe numerous funftions, we 

 mud reflecl that! the (kin is conllanlly cxpofed to tlie action 

 of external caufes, which keep it in a (late of habitual ex- 

 citation, as the contents of mucous furfaces aft on thofe 

 fiirfaces. 



The fivin does not feem to poffefsthe fenfible organic con- 

 traftility ; irritating applications aft only on the capillaries, 

 and therefore produce an effeft, which is not obvious to the 

 eye. Yet the corrugation of the integuments under the 

 ftrong aftion of cold, refembles in fome refpetts the fenfible 

 organic contractility ; this, wMch takes place in the corion, 

 fecms to hold the middle between the two kinds of organic 

 contraftility. 



Pajpve SyinpatJiies. — The animal fenfibility is often brought 

 into adion fympathetically i|) the (kin, by the affections of 

 other fy!lem£. There are various examples of itchinjT, &c. 

 without any derangement of tlie part, to which the fenfation 

 is referred. 



Very often tlie feeling of heat or cold occurs in the ilvin, 

 ■when there is no caufe aftecting the organ to produce fuch 

 fenfations ; there feems to be an erroneous reference of the 

 unpleafant feeling to its foiirce as in the cafe of pains felt 

 in amputated limbs. The (hiverings which occur at the 

 commencement of moll; acute local difeafes are of this kind : 

 there is often a fudden and fympatlictic fenfation of cold 

 o'n the frcin at the moment of the expulfion of the femen ; 

 the (hivering of fear, and the fweat w hich often accompanies 

 it, feem to be of the fame nature.. A fpecies of fympaibetic 

 cold is alfo often referred to the (Iciii at the commencement 

 of digelHon. 



The feeling of heat often occurs fympathetically in the 

 flcin. The flu(hings, which occur fo often and irregularly 

 in different fevers, are well known, and are not attended with 

 any difSgagement of caloric. Thefe feehngs of heat and 

 cold are produced without any alteration of temperature, as 

 fympathetic pains occur witliout the :ii"lion of thofe obvious 

 caufes, wliich give rife to them under other circumftances. 

 In-faft, the fympathics of the animal fenfibihty call into 

 aftion, in each fyilem, the feeling which is habitual to'it. 

 The fame caufe which produces the fenfation of heat or 

 cold in the (Ifin, would have given rife to that of lalfitude in 

 the mufcles, &c. 



The organic properties of the (kin are frequently called 

 into aftion by fynipa'hies : thus cold drinks fupprefs per- 

 fpiration. Augmented cutanfous exhalation follows almolt 

 immediately the introduclioa of warm fluids into the (lo- 

 macFi. The fweat of fear and that of confumption are 

 of the fame nature. Difcafes exhibit to us innumerable 

 varieties of drynefs and moiilure of the organ, phenomena 

 which are generally fympathetic. 



ASive Sympathies. — The irritation of the (kin in tickling, 

 in very fenfible individuals, excites various organs fympa- 

 thetically ; as the heart, producing fainting ; the (loniach, 

 vomiting; an^ the brain, couvulfions. Affeftions of the 

 cutaneous exhalaiits, or of the capillary fyllcm, from which 

 t'''>y arife, aft fympathetically on t»rious organs. Thus 

 v..irm bath di ill; rbs the procefs of digeftion ; while its 

 ce in many cafes allays difordcrs of the ftomach. The 

 I cjf cold on the fnrface, particidarly during fweating, 

 :cc9 feveral fympathetic effefts. We exprefs what oc- 

 . ry inaccurately, when we refer it to the trandation or 

 ...on of the f erfpiratory matter. The organic fenfibility 



of the pleura is fympathetically afTefted by the application 

 of cold to the (kin ; jull as an uterine or nafal hemorrhage 

 may be (lopped. The fupprefTion of tranfpiration is an 

 acceifory circumllance completely foreign to the internal 

 inflammation. If there were no perfpiration at the time 

 that the cold is applied, the inflammation would dill come 

 on. 



The (baking of the mufcles, and the concentration of 

 the pulfe, produced by the weakened aftion of the heart, 

 are phenomena caufed entirely by the aftion of cold on the 

 fl<in. 



The numerous phenomena occafioned by the fudden dif- 

 appearance of cutaneous eruptions fliould be referred to mo- 

 difications of tlie vital properties of the organs, and not to 

 any morbific matter repelled from the flcin. 



The ferous furfaces and the cellular fub (lance on one 

 fide, and the fliin on the other, are often in oppofition in 

 difeafes. Patients never fweat during the formation of drop, 

 fies ; and this drynefs of the fltin is often more remarkable 

 than the fmall quantity of urine. 



Characters nf the I'ilal Propaiies. — I . They vary in the 

 difFenent regions of the body. The palms and foles are the - 

 moft diilinguiflied for their animal fenfibility : the hypo- 

 chondria are fo fenfible in fome individuals, that tickhng 

 will produce convulfions : the anterior and lateral parts of 

 the trunk are more fenfible than the back. The organic 

 properties do not differ lefs ; of r>hich the great fufcep- 

 tibiiity of the face to the influx of blood is a proof. Par- 

 ticular parts are fubjcft to particular cutaneous difeafes,. 

 &c. 



2. IntermifTion of aftion in one rcfpeft, uninterrupted' 

 continuance in another. The former charafter belongs to 

 this fyftem, as to all the fenfcs, in its animal fenfibility. 

 Immediately before ileep comes on, external objefts pro- 

 duce but an obfcure fenfation, which is entirely loll in that 

 Itate, in which animals feem to part with half their exift- 

 cnce. Yet the touch feems to be exerted occafionally while 

 the other fenfes are in repofe : pinch the limb ot-a per- 

 fon fleeping, and he will move it without wakilig, or re- 

 taining any recoUeftion of the occurrence. In its organic 

 fcnfibihty the life of the cutaneous fyftem is uninterrupted ; 

 confequently the functions, over which this property pre- 

 fides, have an oppofite charafter to the preceding. The 

 infenfible tranfpiration goes on continually, although it is 

 more aftive at fome times than at others. 



3. Influence of fex. The animal fenfibility is more acute 

 in women, in whom every thing belonging to the fenfes is 

 more developed, while the power of the mufcles predomi- 

 nates in man. No very fenfible difference can be remarked 

 in the organic properties. 



4. Influence of temperament. The colour and other fenfible 

 properties of the lliin vary in individuals, and thefe va- 

 riations even conftitute charafters of the different tempera- 

 ments. When we fee thefe differences of organization, 

 can we be furprifed at finding that the feiife of touck is 

 acute in fome, dull in others ; that fome perfons are very 

 fnfceptible of tickling, and others almoft infenfible to it ? 

 That the organic fenfibility admits a great quantity of blood 

 into the capillaries of trie face in fome, and rejects it in 

 others ; that fome have a moid and others a dry ilcin ; that 

 there are difpoiitions in individuals to particidai; cutaneous 

 affeftions, chronic or acute ? &c. &c. 



Developement of the ekrmo'ul Syjlem. — The fkin, in the early 

 times of concejition, appears as a vifcid coating, which is 

 gradually coodenfed into a tranfparent layer, torn by the 

 flighted violence, and allowing tlie fubjaccot orgiins, p;ii> 



liculftrly 



