310 PHILOSOl-HICAL TRANSACTIONS. [aNNO 1778. 



shall be spent ; then indeed you are lo throw it away, and supply its place with 

 the lime-water ooze. 



21. In a very few days you will perceive the difference between the activity of 

 the two oozes, the new and old, with respect to penetrating the leather ; and 

 thus, without any kind of loss or waste, you will get rid of all your old liquors, 

 and come speedily into a full stock of the ooze made with lime-water ; and after 

 you have got the new method established, your business will go in a regular 

 course, and one parcel of goods will succeed another, as fast as you can manu- 

 facture and dispose of them. 12. Though it is possible to tan small parcels of 

 'eather, by way of experiment, by the use of lime-water ooze, in a 4th part of 

 the time required, if only common ooze be made use of; yet the business of a 

 large tan-yard cannot be carried on with so much expedition : but even in large 

 works, and in the common course of business, sole leather can be completely 

 tanned and finished, in from 1 1 to 15 months, according to the different weight 

 and thickness of the hides. Buts in, from 8 to ] 2 months, and calf-skins in, 

 from 6 to 12 weeks ; in general, the tanner may save at least a 3d of the time 

 that has hitherto been required. 



23. The leather, manufactured in the new way, is of a superior quality to 

 that of the old tannage, especially the sole-leather, which wears remarkably well, 

 and never shows the least sign of rottenness. 24. Let it always be remembered, 

 that the lime-water is never to be used but when it is sufficiently strong, and as 

 clear as rock water. 25. Whenever you make fresh ooze, you must always use 

 fresh lime-water, and run the ooze through 2 letches ; and the lime-water ooze, 

 when spent, from lying on the leather, is never to be returned back on the bark 

 which is in the letches (as you now return your spent ooze) but must always be 

 thrown away, as being entirely useless ; for which purpose you must contrive a 

 gutter in the tan-yard to carry off the spent ooze. 



26. Tlie letches ought to be under cover, lest the rain get into them and 

 weaken the ooze ; and if the handlers are sheltered, it will be so much the 

 better ; but it is of no importance to cover the vats, provided when the leather is 

 laid away in them, they are kept constantly full to the brim. 27. You must 

 always take care to have a sufficient stock of unslaked lime by you (for if it be 

 slaked, it will not answer to make lime-water :) therefore, get your lime fresh, 

 if possible, from the kiln, and immediately pack it in any kind of old dry casks. 

 Weio-h one of these casks, and it will enable you to ascertain the quantity of 

 lime necessary to be thrown into the cistern each time you begin a fresh brewing 

 of lime-water, and thus save the trouble of repeated weighings ; not that there 

 need be much nicety about the quantity of lime, a score of pounds over or under 

 making no .sensible difference in the strength of the lime-water. 28. Any ex- 



