204 Transactions of (he Society. 



alone of this latter material, so that we may produce a very equal 

 heating from all sides of the sponge preparations. On one side of the 

 oven is a door which flaps downwards, whilst the cover also is made to 

 flap hackwards. Through the latter a thermometer and if desired a 

 recjulator may be put as in an ordinary chemical hot oven. The whole 

 is supported on metal lees of a convenient height. Within is a metal 

 rack with shelves at different heights ; the slides or preparations are 

 placed for the first few days on the top shelf and are afterwards gradually 

 lowered. 



