20 PRACTICAL HISTOLOGY [ll 



water, or with stains soluble in alcohol, by making use of the 

 centrifugal machine 1 to separate them from each fluid added. 



DEMONSTRATION. 



Circulation of blood in the mesentery of the newt 

 to show the platelets sticking for a variable time 

 to the walls of the vessels (cp. Lesson on the Circula- 

 tion). 



1 A convenient form of centrifugal machine is the 'High-speed 

 Medical Centrifuge ' obtainable, with a description of method of use, 

 from most Opticians. 



