On the Atomic Weight of Glucinum. 



5 



The calorimeter employed was an improved form of the instrument 

 described in my former paper (Joe. cit.). The opening and closing of 

 the two sliders, and the movement of the catch to release the substance, 

 were, however, made automatic by suitable electrical connexions. It 

 was thus only necessary to run the calorimeter under the heater and 

 back again in order to transfer the substance from the latter to the 

 former. The calorimeter (M, fig. 1), with its brass casing, and the bent 

 thermometer (£ 4 ), were the same as those used before ; the agitator (P) 

 was worked by a small electromotor (T). Two new heaters were used, 

 one for temperatures up to 150°, and one for temperatures from 150° 



Fig. 2. 



to 300°. The former (fig. 2) consists of a double brass vessel with 

 a thick jacket of slag-wool. The vapour of the boiling liquid passes 

 from -the boiler to the heater by one tube, and leaves by another, is 

 condensed and flows back to the boiler. The liquids used in this 

 heater were methyl alcohol, water, and xylol, but the results obtained 

 with the first-named liquid were inaccurate owing to the small rise 

 (0'6°) in the temperature of the calorimeter. In this apparatus it is 

 possible to obtain a temperature constant to for any length of time.* 

 The heater for high temperatures (A, fig. 1) was made on the 

 pattern described by Lothar Meyerf , the construction of which will 

 be evident from the figure. C is an outer non-conducting casing, 

 L is a ring burner, from which the heated gases pass up through 

 the heater and escape through perforations in the double lid (V) . 

 This heater is mounted on a thick slab of asbestos (D), by means of 

 which it stands on two brass plates (E), which are separated from 

 one another by a coil of thin lead tubing, through which a current 



* This is only true for a liquid with a constant boiling point ; the xylol used had 

 to be fractionated several times before a constant temperature could be obtained, 

 f " Berlin Ber.," xvi, 1087. 



