460 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



PREPARATION OF TRAGACANTH. 



It is said that gum tragacanth mucilage can be prepared 

 much more quickly and of a more uniform consistency by 

 first rubbing up the powdered gum with a little glycerine 

 before the water is added. In this way the formation of 

 lumps is entirely avoided. JV. Zahrt.f. Phar,^ September^lSlO, 

 164. 



gilders' glue. 



A very superior article of the so-called gilders' glue is ob- 

 tained by cutting rabbit-skins into fine shreds, and boiling in 

 water, then turning the mixture into a basket, through which 

 the liquid passes, leaving the refuse behind. About fifteen 

 hundred grains of sulphate of zinc and three hundred and 

 seventy-five of alum are then to be separately dissolved in 

 pure boiling water, and poured into the first-mentioned liquid, 

 and the whole well stirred together while hot. The mixture 

 is then to be passed through a sieve into a rectangular box, 

 in which the jelly remains twenty-four hours in winter, or 

 about forty-eight in summer. The mass, now having become 

 solid, is to be separated from the box, and cut into slices of 

 proper thickness, and laid upon nets to dry either in the open 

 air or by means of some kind of artificial heat. 14 (7, CXCIV., 

 516. 



cement for bottle-corks. 



An excellent material for sealing wine-bottles is said to 

 consist of two parts of wax, four parts of colophony, and two 

 parts of pitch. 15^4,1870,107. 



PREPARATION OF GELATINE FROM BONE. 



A new process of obtaining gelatine from bones, for the 

 purpose of making glue, consists in exposing them to the ac- 

 tion of benzine. 4 B, 1870, 24. 



PRESERVATION OF PLASTER AGAINST VINEGAR FUMES. 



Much difficulty is experienced in vinegar factories, and oth- 

 er establishments where acid fumes are disengaged, in pre- 

 venting the plastering or whitewash from falling oft*. This 

 may, however, bo prevented, it is said, by washing the walls 



