Heat by Conduction in Bone, Brain-tissue, and Skin. 191 



Times required to traverse 1 millim. of each of the tissues, calculated 

 for a difference of 0°*1 C. 





Bone. 



Brain. 



Skin. 



4 - 9733 seconds. 

 7-4480 

 35053 „ 



5-3986 seconds. 



8-4941 



3 6853 



7'6267 seconds. 



9-8057 



3-3333 



Table VI ogives the results obtained at the end on the several times 

 adopted in the preceding tables as bone and brain. 



Table VI. — Effects of o- l C. difference of temperature through 3 

 millims. of sheep's scalp. 1° of galvanometer is equal to =, 0006742 

 C. ; and 0°\1 C. is equal to 148°'316 of galvanometer. 



Time from the 

 moment of 

 contact of copper 

 plate, on which 

 the piece of skin 

 rested, and water. 



Averages. 



Maxima. 



Minima. 



Degrees 

 of 



galvano- 

 meter. 



Thermo- 

 metric 

 values. 



Degrees 

 of 



galvano- 

 meter. 



Thermo- 

 metric 

 rallies. 



Degrees 

 of 



galvano- 

 meter. 



Thermo- 

 metric 

 values. 



At the end of — 



1 min. 15 sec. 



2 „ „ 

 4 „ „ 

 6 „ „ 



17-191° 

 31-241 

 59-208 

 80-766 



0-01159° C. 

 0-02106 

 0-03992 

 005445 



21-120° 

 38-808 

 83-952 

 96492 



0-01424" C. 

 0-02616 

 0-05660 

 0-06505 



10-576° 

 20-898 

 35-861 

 63-884 



000713° C. 

 0-01409 

 0-02417 

 0-04307 



Percentages of heat transmitted, deduced from the above values. 



Times. 



Averages. 



Maxima. 



Minima. 



2 „ „ 



4 „ „ 



6 „ „ 



11'597 per cent. 

 21-063 

 39 921 

 54-452 



14-239 per cent. 

 26-165 

 56-603 

 65-058 



7 - 137 per cent. 

 14-090 

 24-179 

 43070 



It will, at once, be evident, that, although, the pieces of skull and 

 of cerebrum are two and a-half times thicker than the pieces of skin, 

 yet the amount of heat transmitted by the latter is considerably less 

 than the amount transmitted by the former, with the exception, 

 that the minimum values of scalp are higher than the corresponding 

 values of brain-tissue, and approach somewhat closely to those of 

 skull. 



