101 



cylindrical wall we shall mention the analysis of the freez- 

 ing curves obtained with arrangements of the type repre- 

 sented in Figure 3. A cylindrical shell of living tissue AC, 



Fig. 3. Arrangement of apparatus illustrating the application of the 

 ' ' Problem of the multiple cylindrical wall. ' ' 



slipped around the bulb B of a thermometer, is placed in 

 the medium D contained in a tube E, which is itself im- 

 mersed in a cooling bath H. During freezing, heat is then 

 transmitted from the mercury of the thermometer and 

 from the freezing object to the external bath, through the 

 many cylindrical walls which are the glass of the ther- 

 mometer, the tissue, the medium and the tube E. In such 

 cases important errors have resulted from a too candid 

 use of thermometers as temperature-meters, as their name 

 suggests them to be, instead of as heat conductors which, in 

 the last analysis, they are. 



2. The Problem of the Wall, in the Variable State. The 

 essential laws governing the relation between the tempera- 



