294 CEMENTS. 



The same may be done with glovers* cuttings of 

 leather, which are dressed with alum instead of 

 being tanned ; this will make a colourless glue. 



A good Glue for Sigii-BoardSy or any thing that 

 must sta?id the Weather. 



Melt common glue with water to a proper con- 

 sistence ; then add one eighth of boiled linseed oil, 

 dropping it into the glue gently, and stirring it all 

 the time. 



A very strong glue is made by adding some pow- 

 dered chalk to common glue. 



Another that will resist water is made by adding 

 half a pound of common glue to two quarts of 

 skimmed milk. 



Preparation of Lip Ghwyfor cementing Taper ^ Silk, 

 thin Leather, ^c. 



Take of isinglass glue and parchment ghie, each 

 one ounce ; of sugar-candy, and gum tragacanth, 

 each two drachms ; add to them an ounce of water, 

 and boil the whole togetlier, till the mixture ap- 

 pears, when cold, of the proper consistence of glue. 

 Then form it into small roils, or any other figure 

 that may be most convenient. 



This glue may be wet witli the tongue, and 

 rubbed on the edges of the paper, silk, &c. that are 

 to be cemented, which will, on their being laid to- 

 gether, and suffered to dry, unite as firmly as any 

 other part of the substance. 



