INTRODUCTION. 



xli 



Freezing-Chamber. This consists of a zinc cylinder () \\ inches deep by 2\ wide, closed 

 above and below. An aperture (/), f of an inch across, is made on either side of the cylinder 

 to allow the admission of the nozzle of the spray-producer, as also for free evaporation of 

 ether, a large proportion of which, however, condenses on the sloping false bottom (g) and is 

 conveyed off by the tube (/) into a bottle attached to it. 



Fig. 21. THE ETHER FREEZING MICROTOME OF DR. BEVAN LEWIS. This instrument is made by 

 Mr. Gardner, South Bridge, Edinburgh. 



The instrument is simple, efficient, and compact, and enables one with a minimum 

 expenditure of ether to obtain the most delicate sections of any tissue not more resistant than 

 cartilage. 



A little experience in the use of the instrument enables the operator to freeze so rapidly 

 that he will scarcely feel that it repays him to collect the condensed ether. 



