5i5 D'tre^lms Jor Tilmnf^g^ t^i. 



It is fcarcely niecefrary to add, that tte bark as well as tb« 

 hrfHlions llioirld be carefully proledltd, Iro&i raifi, fnow, aiid 

 hail, vbich. would injure them rtiKterially ; and tven from 

 froft, if poflible, bccaofe the operation of the liquor when 

 frozen is totally fufpended. 



%. Ywrt or lix days aregetierally fu flioi en t for the irtimerfion 

 of the hides in the fame vats, as by that time they come 16 

 an equilibrium, in point of faturation, with the liqilor; that 

 is to fay, they acquire all the ftrength the liquor ca!n give 

 thcni. iljey are then to be flvifted mto a Uronger infufion, 

 vbere they may remain the famte number of days. In mild 

 weathc-. if the liquor is of a proper ftrenglh, three or four 

 Hnmcrfimis, of five or fix days each, will be fufficieht to tan 

 the bides, wiiich in the old mode require eighteeti or twenty 

 months to be completely tanned. To keep them io«c;er in 

 the fanie liquor would be fo much lime loft, as in making 

 the infufions it would be a lofs of time to let the liquor (ian^ 

 more than a conple of hours on the fame fan. ft is not the 

 length of time during which the fame watQf ftands on thie 

 tKiric, but the number of waterings, that wvll c<>h>pktely fe- 

 parate the tanning principle from it. As:the heavieft arid 

 T>e(i part of the liquor always faJls to tb€ bottom of the vats, 

 it ihould be ftirred up from time to time. 



3, The ufe of the folution of glue (liould not be neglcfted, 

 Since thb folution has been made known as a tell f<w afcer- 

 taining the prefence of the tannii'ig |)rinciplt: m tiie infufions 

 ©f difterent kinds of bark, a great variety o!t them have been 

 already found, and many others may yet be difcovered, to be 

 excellent fubftitutes for oak bark ; and in prop^^ftion as their 

 ufe becomes general it will necdiarily lower the j>refent high 

 price of the latter article, and fave many young oaks. 



Ai^iongft tlic barks already found, by means of tliis teft, 

 «) contain the taaming principle in a greater or lefs prapor- 

 ijoti, the principal are thofe of the following trees, vi^. 

 willow, aflij hazel, Spanilli clieftnut, pOijvlar, fallow, cherry- 

 tree, bifc5i, fycamore, plum-tree, beeclis, aind older. 



4. In tiW"» yards where there is not a fufficrent body of 

 runniiig water for foaking and wailiing the fkins, in order to 



. txtra^t the lime from them, tfee prefctnt mode of cxtra<3:ing 

 il in grainers, bv means of pigeoji's dtmg, hen's dvtiag, or 

 wher alkaline fubftances, may be continued ; l>*it the (kins 

 ftonld *»eveT be pnt into the fame liquor in ivhich bides tm- 

 ifenired wilk tiic gallfe and vitriolic acids have beeu tanned. 



■ "ilie ufe of thefc acids is not abColutiely i>eceffiiry either to 

 fbort^u the ticrae 'or.prodirce gxiod tealher^ but wiicn ufed will 

 be found to add confiderabiy to its weight, 



5. By 



