94 



BACTERIOLOtiY. 



pleted, ill a mixtiu-e of ether ami alcoliol for an liour or more. 

 They are then transferred to a sohitioii of eelli,>i(Uii in eijual parts 

 of ether and alcohol, and left there, usually foi- several lioiu>. 



The piece of tissue is then placed in a glass capsule, and some 

 of the celloidin solution poured over it. The capsule can be placed 



Tig. 27. — Swift's Fkeezing !Mickotome. 



bodily ill 60 to 80 per cent, alcohol, and left until the foUo^viiii;- 

 morning. The celloidin "will then lie of the consistency of ^\-ax. 

 The piece of tissue is next cut out, and after trimming off superlluons 

 celloidin is put in ■water until it sinks. It is then transferred to 

 gum, and frozen and cut with a freezing microtome. 



For cutting with Jung's microtome, the tissues are embedded 



