Materia photographica : a treatise on the manufacture, properties, and uses of the substances employed in photography (1891)
Leaper, Clement J · London : Iliffe · leaf 27
Digestion is a process which has for its object to cause two •substances to unite by maintaining them for seme time at a more •or less elevated temperature. It is evident that one at least of the substances must be a liquid or a solid in solution. 8. Decantation is the separation without filtering… … neck of the vessel, presumably a beaker, is greased, and the liquid guided into another vessel by the aid of a previously wetted glass rod, held firmly against the side of the beaker, as shown in the figure. On a larger scale the syphon is employed. 9. Pulverisation means reducing a substance to…
Photography
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
