

BAIRD &.TATLOCK (LONDON) LTD. 



4682 4683 4684 



4682 Oxy -Hydrogen Gas Generator .... . . 12 6 



4683 Hesse's Apparatus for the bacteriological examination of air, on tripod stand, complete 1 16 



4684 Carbonic Acid Meter, or Air Tester, Wolpert's, pocket size. The essential principle 



involved in the use of this convenient and novel apparatus consists in a known volume of 

 air being admitted and shaken up with a measured quantity of sodium carbonate, coloured 

 with phenol-phthalin ; the proportion of carbonic acid present in the air being deduced 

 from the number of cubic centimetres required to decolourise the red solution . . 14 



4685 

 4685 T Palladium Tubes 



4686 T Palladium Tubes 



4686 



Price about 150 

 Price 150 





CROSS STREET HATTOTST GARDEN, E- C 



