It often happens that materials which are dissolved by the ordinary solvents in use are to be collected in open dishes in order that their properties may be studied. At the same time large quantities of solvents must be used, and it is desirable to have some method of recovering them. The device shown in [Fig. 26] has been found to work excellently well for this purpose.[22] It consists of a steam-bath, W, and a bottle, B, with the bottom cut off, resting on an iron dish, P, containing a small quantity of mercury, enough to seal the bottom of the bottle. The dish containing the solvent is placed on the mercury, and the bottle placed down over it, forming a tight joint. On the application of steam the solvent escapes into the condenser, C, and is collected as a liquid in the flask A. In very volatile solvents the flask A may be surrounded with ice, or ice-cold water passed through the condenser. When an additional quantity of the solvent is to be added to the dish for the purpose of evaporating it is poured into the funnel F, and the stopcock H opened, which allows the material to run into the dish in B without removing the bottle. In this way many liters of the solvent may be evaporated in any one dish, and the total amount of extract obtained together. At the last the bottle B is removed, and the extract which is found in the dish is ready for further operations.
AUTHORITIES CITED IN PART FIRST.
[1] Sidersky: Traité d’Analyse des Matières Sucrées, p. 311.
[2] Die Agricultur-Chemische Versuchs-Station, Halle a/S., S. 34. (Read Dreef instead of Dree.)
[3] Report of Commissioner of Fish and Fisheries, 1888, p.686.
[4] Vid. op. cit. 2, p. 14.
[5] Journal of the American Chemical Society, Vol. 15, p. 83.
[6] Chemical Division, U. S. Department of Agriculture, Bulletin No. 28, p. 101.
[7] Not yet described in any publication. Presented at 12th annual meeting of the Association of Agricultural Chemists, Aug. 7th, 1895.
[8] Vid. op. cit. 6, p. 100.