denser. The vapour generated in the flask passes by means of 

 the side tube into the condenser and drops back upon the sample, 

 and the condensed solvent with the oil now in solution pa- 

 through the siphon into the flask, to be again evaporated until 

 the fat or oil is completely extracted from the sample. 



200. Fat extraction apparatus, six forms, namely, 

 Tollens', Kreussler's, Schwarz's, Gawalowsky's, G-awa- 

 lowsky's with Dreschel funnel, and Soxhlet's. Prices 3s., 

 9s., 7s., 9s., lls., and 5s. 



1886. Exhibited by Townson $ Mercer. 



These are arrangements by which a volatile solvent, such as 

 ether, benzine, &c. is brought upon a fatty body and after ex- 

 tracting some fat is distilled and brought back upon the body, 

 thereby using the same solvent repeatedly in one operation. 



201. Fat extraction apparatus, Jago's. Price 3s. 6d. 

 1886. Exhibited by J. Orme Sf Go. 



202. Backer's viscosity apparatus for testing lubri- 

 cating oil. Price 21. 10s. 



1886. Exhibited by Townson fy Mercer. 



The viscosity or fluidity of oils is determined by ascertaining 

 the rate at which they flow through a given aperture. 100 c.c. 

 or some other definite volume of the oil to be tested should be 

 poured into a burette furnished with a glass stopcock. The 

 burette is surrounded with a glass cylinder fitted with an 

 arrangement by which steam can be made to circulate through 

 it, and bring the burette to a definite temperature, which is 

 indicated by a thermometer. When the oil has reached the 

 desired temperature, the top of the burette is fully opened 

 and the number of seconds required for the emptying of the 

 burette noted. The time which elapses gives a relative measure 

 of the viscosity of the oil. 



203. Specific gravity bottle with thermometer, 

 designed for butter testing. Price 7s. 6d. 



1886. Exhibited by J. Orme fy Co. 



204. Soleil-Scheibler polarimeter for the determina- 

 tion of sugar in an aqueous solution. 



E. 55. 1888. Made by Schmidt Haensch, Berlin. 



This apparatus consists of a brass stand on which rests, with 

 horizontally rotating motion, a blackened metal trough, in 

 which the experimental tube is laid, the upper part of the 

 trough serving as a cover, to be shut down to exclude extraneous 

 light The end of the trough next the light is connected with 



U 64846, F 



