BAIRD &TATLOCK (LONDON) LTD. 



428 



429 



430 



A430 



431 



432 



each 





427 Gas Regulator, Page's, unfilled 



428 Gas Regulator, Reichert's, filled with mercury 



429 Gas Regulator, Reichert-Muencke, improved form, with stopcock to byepass, filled with 



mercury . . . . . . . . . . . . . . . . each 



430 Gas Regulator, Bunsen-Kemp, unfilled . . . . . . . . ,, 



A430 Gas Regulator, mercury-toluol, as described in Findlay's " Practical Physical Chemistry." 

 Price, unfilled . . . . . . . . . . . . . . each 



431 Novy's New Thermo -Regulator. Size of cylinder, E, 15 by 120 mm. This is especially 



useful for regulating the temperature of a Hofmann water bath, or of a small incubator 

 such as Nuttall's. Price unfilled . . . . . . . . . . each 



The diagram illustrates the construction of the regulator. Part A is provided with two lateral tubes which 

 have a ground internal surface. Part B is ground to fit the preceding. It is provided with an opening through 

 which the gas passes into the interior. The lower portion of B, opposite the outflow tube, is ground on the inside, 

 and has a small opening one millimetre in diameter. The neck above is likewise ground internally. The lower 

 portion of the tube B when placed in position inside of part A , should come within one or two millimetres 

 of the bottom of the cup. In this case the first drop of mercury, as it issues from below, shuts off the outflow 

 of gas. 



The upper part of part C is solid, whereas the lower portion is hollow. The lower portion of C is ground to 

 fit exactly the corresponding part in B. The upper portion of C is a ground stopper fitting into B. 



The manipulation of the thermo-regulator is very simple. The gas enters through the upper lateral tube. 

 If it is desired to diminish the inflow of gas. this can be done by turning B. By turning part C, the minimum 

 outflow of gas can be regulated at will. To fill regulator, close the upper side tube by the ground tube, 

 exhaust bulb by lower side tube, invert regulator and connect upper side tube to a supply of toluol, turn ground 

 tube and allow toluol to enter until the bulb is filled. Fill mercury into bulb and tube until it appears as 

 on sketch. 



432 Novy's New Mercury -Toluol Thermo -Regulator, with glass stopcock for adjusting the 



level in mercury column. Size of cylinder E, 15 by 120 mm. This is especially useful 

 for regulating the temperature of a Hofmann water bath, or of a, small incubator such as 

 Nuttall's. Price unfilled . . . . . . . . . . . . each 



1 9 



050 



070 

 076 



060 

 10 6 





12 



CROSS STREET HATTON GARDETST, 



