270 A SUBSTANCE FOR GLUE. 
The process of converting gluten into vegetable albumen may be ac- 
celerated in the following manner : — The gluten is put into a vessel or 
boiler, and heated by steam, or in a water bath, but the heat must only 
be sufficient to soften the gluten, and should vary from 105? to 140° 
Fah. The gluten combines and unites with the water which became in- 
corporated with it in the operation of kneading ; part of the water is, how- 
ever, evaporated during the process of fermentation, and that the time 
required for drying the modified gluten, in the manner before described 
is reduced. The water and gluten, when united, form a perfectly homo- 
geneous mass of a thin pasty consistency, which is removed from the 
vessel, and dried, as before described ; or the drying chamber may be 
heated by steam, care being taken that the heat is very moderate. When 
dry, the vegetable albumen takes up the greater part of the water which 
it has lost through evaporation during the process of desiccation. In order 
to dissolve it, it is put to steep, for about forty-eight hours, in cold 
water, and, by preference, in soft water ; during this time it should be 
frequently stirred. Before being used the liquid should be diluted 
with water, and well stirred and shaken up, so that the whole mass of 
solution is perfectly homogeneous. The quantity of water for dilution 
must be regulated according to the purpose for which the solution is 
required. One pound of the so-called vegetable albumen to one pound 
and a half of water will give a solution which may be used as a substi- 
tute for the strongest glue or gelatine, and which resists moisture to a 
great extent, and is not influenced by heat. 
The solution may be used cold, and will retain its properties from 
ten to fifteen days in summer, and twice as long in winter ; that is to say, 
if it is kept cool, and, if possible, in a current of air. 
This vegetable albumen is applicable, first, for uniting pieces of 
wood, in lieu of glue or gelatine ; secondly, for uniting pieces of 
porcelain, earthenware, glass, enamel, and other similar articles ; thirdly, 
for uniting pieces of leather, skin, linen, paper, pasteboard, and other 
similar substances ; fourthly, for rectifying, clarifying, strengthening, 
preserving, and generally improving malt liquors ; fifthly, for sizing 
paper and warps ; sixthly, for sizing, dressing, stiffening, and thickening 
every description of woven fabrics and silks, instead of, or combined 
with, animal gelatine, gum, dextrine, fecula, or other substances ; 
seventhly, for fixing all colours, except ultramarine blue, in printing 
fabrics ; it is requisite to add from ten to twenty-five per cent, of acetic 
acid, of the strength of seven or eight degrees of Beaume's hydrometer, 
to the vegetable albumen, which is then thickened in the ordinary 
manner with fine wheat flour, starch, fecula, or dextrine of wheat, care 
being taken to boil the same from ten to thirty minutes, according to 
the degree of concentration, and the consistence of the colour required. 
Before use, the mixture should be allowed to cool sufficiently to avoid 
coagulation. For ultramarine blue, a little ammonia is used, instead of 
the acetic acid ; the vegetable albumen must then be dissolved in, or 
