8 



52. Desiccators of different patterns : 

 Bohemian glass, with zinc support. Price 3s. 

 Bell glass, ground glass plate, and sulphuric acid 



dish. Price 5s. 6d. 



Thorpe's with dome cover. Price 4s. 6d. 

 Form with flat cover. Price 3s. 6d. 

 Form with bell glass and zinc plate, on stand. 



Price Ss. 6d. 

 1876 and. 1886. Exhibited by J. Orme $ Go. 



53. Desiccator, 4 in. diam., according to Dr. Schiff, 

 with stopcock and glass hook, arranged so as to be 

 readily evacuated. Price 7s. 6d. 



1886. Exhibited ~by Townson fy Mercer. 



54-. Drying closet for precipitates, with mica plates. 

 E. 138. 1877. Made by Max Raphael, Breslau. 



55. Water oven and condenser. Price 31. 15s. 



1886. Exhibited by Townson fy Mercer. 



56. Water bath, Bunsen's, with regulator. Price2l. 10s. 

 1876. Exhibited by J. Orme fy Go. 



57. Gas regulators, two forms, Tollens' and Lothar 

 Meyer's. Prices Is. 6d. and 6s. 



1886. Exhibited by Townson fy Mercer. 



These are used for regulating the supply of gas to burners. 

 In Tollens' form there is a quantity of air shut in one bulb by 

 mercury. This air expands and contracts by variations of tem- 

 perature, and thereby forces more mercury into or withdraws it 

 from the other bulb. Into this latter bulb the gas enters by a 

 tube, which is regulated so that the mercury will just touch the 

 lower end when the bath to be heated has obtained the desired 

 temperature, and a diminution in the gas supply will thus be 

 brought about which will effectually prevent the bath from 

 attaining too high a temperature. Lothar Meyer's form and 

 many others are based upon the same principle. 



58. Gas regulator, 



1881. Exhibited by J. Garbutt. 



59. Gas regulators (2), Jago's. Price 3s. 6d. each. 

 1886. Exhibited by J. Orme $ Co. 



60. Furnace, Bunsen's, with 24 burners and combus- 

 tion tube. Price 41. 



1876. Exhibited by J. Onne fy Co. 



