No. 216.] 187 



improvements had been adopted with the lime process, of strong U 

 quor and quick tanning, it is not yet certain that the same results 

 would not have been attained. 



Salted hides do not require more than two-thirds the time to soak; 

 but generally rather longer to sweat. After the hides are prepared 

 for tanning, the next process is, what is commonly called "handling,*' 

 which should be performed two or three times a day in weak " ooze," 

 until the grain is colored. New liquors, or a mixture of new and 

 old, are preferable for Spanish or dry hides — old livuor for slaugh- 

 ter. They are then, after a fortnight, laid away in bark, and 

 changed once in tw^o to four weeks, until tanned. Much care and 

 judgment is requisite in proportioning the continually increasing 

 strength of the liquors to the requirements of the leather in the dif- 

 ferent stages of this process. 



The liquors should also be kept as. cool as possible, within certain 

 limits, but ought never to exceed a temperature of eighty degrees; 

 in fact, a much lower temperature is the maximum point, if the 

 liquor is very strong; too high a heat, with a liquor too strongly 

 charged with the tanning principle, being invariably injurious to the 

 life and color of the leather. From this it would seem that time is 

 an essential element in the process of tanning, and that we cannot 

 make up for the want of it by increasing the strength of the liquor, 

 or raising the temperature at which the process is conducted, any 

 more than we can fatten an ox or horse by giving him more than 

 he can eat. 



It may be questioned (if anything may be doubted in the present 

 improving age,) whether any patented scheme for the more rapid 

 conversion of hides into leather, will be found, on the whole, to 

 have any practical utility. 



I have mentioned the injurious effects resulting from too strong a 

 solution of the active principle of the bark; on the other hand, the 

 use of too weak solutions is to be avoided. Hides that are treated 

 with liquor below the proper strength, become much relaxed in their 

 texture, and lose a portion of their gelatime The leather necessarily 

 loses in weight and compactness, and is much more porous and per- 

 vious to water. The warmer these weak solutions are applied, the 

 greater is their loss of gelatine. To ascertain whether a portion of 

 weak liquor contains any gelatine in solution, it is only necessary to 

 strain a little of it into a glass, and then add a small quantity of a 



