242 farmers' and MmmANICs' JOURNAL. 



be effected in tanning, by using my apparatus. A quantity of bark 

 that had been thrown out of the vat for a day or two, and consid- 

 ered as spentj was put into the cistern and steam applied. It was 

 estimated, that one-half as much tannin was extracted, as had been 

 before by the common process. 



Other experiments were instituted upon bark treated by diffe- 

 rent methods, with similar results. WM. COBURN. 



We, the unders!i;ned, have examined Mr. VVm. Coi5U!1n's appa- 

 ratus for extracting tRuniu by steam, and are coiiviiiccd that more 

 taniiin can be extracted by his mode, than by any other with 

 which we are acffuainted. 



BENJAMIN COOK, ^ 



BENJAMIN ELWELL, | 



HENRY EEEMAN, }- Tanners. 



MYRICK HOPKINS, | 



BENJAMIN WEYMOUTH, j 

 Gardiner, Xov. 17, 1828. 



On the Manufacture of Glue, or Size, for the use of Weavers, Pa- 

 per-hanging Manufacturers, <^-c. 



Glue is made from hides, skins, and pelts ; the skin of the ears, 

 legs, &c. ; and the older the animals are producing them the better. 



Hidt-roundings are the best material for this purpose : viz. the 

 clippings of hides, wl)ich have only been limed; as leather which 

 has been tanned, or dressed in oil, is of no value for glue or size ; 

 except for the use of the black paper-case makers, who use tanned 

 leather for making their glue. 



The proportion of their value for this use is nearly as follows : — 

 112lbs. of the hide-roundiiigs are equal to making 56lbs. of glue •, 

 the same quantity of chamois-leather or glovers' clippings, not 

 oiled nor tanned, or of alumed or whitlawed leather, to 46lbs. of 

 glue ; of hare and rabbit skins, (which are never limed, and are 

 mostly used by buckram-stifleners and linen-dyers, in consequence 

 of their not having any lime or alum in them,) to 35lbs. of glue ; 

 also the same quantity of fellmongers' shreds yield from 25 to 28lbs, 

 of glue ; and of parchment slips or cuttings, from 14 to I6lbs. 



A great deal, however, depends upon the various articles enu- 

 merated, being perfectly free from lime, dust, or dirt, their perfect 

 state of dryness, and their good condition. 



The expenses of boiling them into glue are much reduced when 

 the various articles have been soaked in water for 24 hours pre- 

 vious to boiling them in other fresh water. 



The quantity of water must be regulated by the strength of the 

 glue or size .required ; allowing one pint of water for an ounce of 

 glue, or two gallons for a pound of glue, for single size. 



The hide-roundings require one gallon of water for 16 ounces ; 

 alumed leather, chamois leather and glovers' clippings, one gallon 

 per 20 oz. ; hare and rabbit skins, one gallon per 24 oz. ; fell- 



