-t7* FffpiraiifM ff LeitlJ-rr: 



in order that sacIj of the pupils might himfcif repeat the experiments, ToUow the (!««■ 

 tail of all the procefies, and render himfelf completely mailer of the method. We could 

 have wllhcd to render an exaft account of the two lectures delivered by Citizen Scjuin at 

 the fchool ; but circumftances oblige us to confine our narration to the principal obje(3s. 



Want is the parent of the arts. Though man in the poflcffion of all his forces is formed 

 to fupport the difference of feafons and climates ; though the parts of his body which are 

 fubjecled to preHure, as in quadrupeds, are fo ditpofed as to acquire by habit and excrcife a 

 degree of denfity and compartnefs, which renders them little fenfible to the aftion of foreign 

 bodies : yet accidents, and circi;mftances which it is eafy to fuppofe, have determined him to 

 feek the means of fecurin_:; his feet from the impreffion of an unequal, flinty, or humid foil. 

 The fliepherd mull have firft made ufe of foft and flexible bark, mats, and fimil.ir fabrica- 

 tions of diflcrent kinds ; the hunter muil have taken a piece of the fredi Ikin of fuch animals 

 as fcrveJ for his fupport, which he mud have fafliioned, modelled upon his foot, and retained 

 with (Iraps *. Th^fe fimple means are fulhcient in a climate which is ufually dry ; but they 

 would be of little advantage on wet ground, or in a climate fubje£l to the alterations of wet 

 and dry weather. 



Skins fwell up, and become foft, by molfturc. which renders them permeable to water. 

 Hence they are eafily deflroyed by the putrid procefs which enfues, and they become dry 

 and brittle when the moifture is evaporated. Accident, no doubt, occafioncd the difcoyery 

 of the means of preventing thefe inconveniences by the ufc of certain vegetable fubflances, 

 particularly the bark of oak. It was feen that Ikins prepared with thefe fubllances acquired 

 new properties; that without lofing their flexibility they became lefs permeable to water; 

 more firm, more compaft, and in fonae raeafure incapable of putrefa£lion. Thefe obferva- 

 tions gave birth to the art of the tanner. 



This art, no doubt of higli antiquity, becaufe founded on one of the earlieft wants of man 

 in fociety, comprehends a fuccelTion of procefl'es which was executed by habit and imitation, 

 without a knowledge of the eflential objedls. The preparation of ikins accordingly required 

 feveral years, and frequently, in fpite of the care, expence, and flownefs of the operation, 

 the tanning was incomplete ; the ikin formed a foft and porous leather, which was foon 

 deflroyed by moifture. Thefe defeifls efTentially fprung from ignorance of the true princi- 

 ples of this operation, becaufe no difcovery had been made refpefting the action of tan 

 upon the Ikin, and the circumftances or conditions which might accelerate or retard the 

 procefs. 



To arrive at this knowledge in an accurate manner, it is neceiTary to confider, firft, the 

 nature and properties of tan, andfecondly, the ftrufture and compofition of the (kin. 



We fhali not enter into the detail of fuch precautions as are requifite in the choice of oak 

 bark, the time and manner of feparatlng it from the tree, preferving it, or pulverifing it. 

 It will be fufHcient for our objei.^ to remark, that water poured into a veflel upon tan ac- 

 quires, after fome hours infafion, at the common temperature of the atraofphere, a brown 



* According to the rclationt of travellers, thefe ufagcs arc (till to be found among certain nations, Sparman 

 affirms, that ihe Hottentots make their (hots with a piece of frelh (kin, the edges of which they raife up, and 

 tie with ftraps ; the hairy Me is outwards. No other preparation is made than to ben and moiften the (kin. If 

 it be flrong and thick (fuch is the (kin of the buffalo, for example), it it left for fome hours in cow-dung, 

 wbidi reniJcrt it foft gnd flexible. 



4 colouN 



