THE RMO-REG ULATORS 



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central cavity is subdivided by five double -walled 

 partitions (in which water circulates in connection with 

 the water tanks at the top and base of the incubator) 

 and again by iron shelves to form twenty-four pigeon 

 holes. Into each of these slides an iron drawer 35 cm. 

 long X 12 cm. wide X 22 cm. high forming a self- 

 contained incubator. The drawer is fitted with a 

 wooden form to which is fixed a handle and a numbered 

 label. The thermo-regulating apparatus is the well- 

 known Hearson capsule. 



Fio. 114. Cellular incubator. 



Two incubators at least are required in the labora- 

 tory, for the cultivation of bacteria the one regulated 

 to maintain a temperature of 37 C., and known as 

 the "hot" incubator; the other, 20 C. to 22 C., and 

 known as the "cool" or "cold" incubator. 



Two other incubators, regulated to 42 C. and 60 C. 

 respectively, whilst not absolutely, necessary very soon 

 justify their purchase. 



Thermo regulators. The thermo-regulator is the 



