ART OF MAKING GLCE. 23$- 



III. 



An Account of the Art of ?naking Glue. In a Letter from 

 Mr. John Clennel. 



T 



dear sir, Nezvcajllc,June 21, 1802. 



HE following attempt to develope the " art and my fiery" Great advantage* 

 of glue-making is at your fervice, if you think it worthy a ^j report of '* 

 place in your very valuable mifcellany. The improvement of manufa&crics* 

 any manufacture depends upon its eafy accefs to men of fcience, 

 and a prudential theorift can never be better employed than in 

 attempting to reduce to regularity or to fyftem the manufac- 

 tures that may fall under his attention. In conformity to the 

 fir ft principle, I made fome notes whilft vifiting a glue manu- 

 factory a few years ago iri Southwark, and thofe, interwoven 

 with the remarks on that fubject of fome chemifts of the firft 

 refpeclability, I take the liberty of fending you: at the fame 

 time I muft beg of you, or your correfpondents, that where it 

 may be corrected in any manner, it may be done, and I thai! 

 feel my f elf obliged by the attention. 



Glue is an infpiffated jelly, made of the parings of hides or GIue »« made 

 horns of any kind, the pelts obtained from furriers, and the h ^™ re & c * 

 hoofs and ears of horfes, oxen, calves, fheep, &c. quantities of 

 all which are imported in addition to the home fupply, by many 

 of the great manufacturers of this article : thefe are fnii digeft- Cleaned from 

 ed in lime water, to cleanfe them as far as it can from the gre * c by , lime ~ 



' water j then 



greafe or dirt they may have contracted ; they are then fteep- fteeped in dean 

 ped in clean water, taking care to ftir them well from time to) va . t ; cr J \ ciraincd > 



• r 11 i -, • , , r i boi,ed 'n water j 



time ; afterwards they are. laid in a heap, and the luperabun- clarified by alum 



dant water preffed out; then they are boiled in a large brafs or ,,me 3 ftain- 



caldron with clean water, (kimming off the dirt as it rifes, and fubfidence • 



further clean fed by putting in, after the whole is difTolved, a a S ain - boiled to 



little melted alum or lime finely powdered, which, by their de-^J^y-'poured 



terfive properties, flill further purge it : the (kimming is con- into moulds ,* 



tinued for fome time, when the mafs is firained through bafkets, ^. ut ' V°, r ~ . . 



' , .... t,ons » a nd dncf 



and fuffered to fettle, that the remaining impurities, if any, on a net. 

 may fubfide ; it is then poured gently into the kettle again, 

 and further evaporated by boiling a fecond time, and ikimming, 

 until it becomes a clear but darl^im brown colour: when it is 



thought 



