Franz, Sensations Follownig Nerve Division. 225 



against a steam radiator and produced a burn about 1 cm. in diameter, 

 without appreciating that his hand was in contact with a hot surface. 

 This burn did not heal, as Head has noted in similar cases, as 

 rapidly as burns on noruial parts, and it was over ten weeks before 

 this area of the side of the hand t(K;)k on a healthy appearance. 

 Duriug this time no pain or feeling of temperature could be ob- 

 tained from this part of the hand. Temperatures as high as I dared 

 use in the experiments, without causing a burn^ were not felt. In 

 the same way low temperatures were not appreciated on this part 

 of the arm and hand. A test tube, the temperature of which had 

 been lowered to ■ — 5° C. was not felt and during cold weather the 

 patient had to depend upon the sensations from the thumb and the 

 radial part of the arm to determine when the hand should be covered. 



In the areas of the hand and arm in which protopathic sensibility 

 remained, the extremes of temperature were easily appreciated, al- 

 though the medium temjjeratures did not call forth a sensation. In 

 the area retaining also the epicritic sense, however, both extreme 

 and medium temperatures were readily appreciated. 



In the experiments with my subject, I used heated or cooled test 

 tubes, 12.5 mm. in diameter with hemispherical bottoms. These 

 were filled with water and in each tube a thermometer was inserted 

 so that the temperature could be read directly after or before stimulat- 

 ing any part of the skin. The tubes were placed on the skin and 

 pressed only Avith their own weight. It was found that at no place 

 of stimulation did an area more than 8 mm. in diameter rest upon 

 the skin. For cold sensations the test tubes were cooled by being- 

 placed in a mixture of ice and salt, and for the lowest temperature 

 the tubes were cooled to — 5° C. For lesser degrees of cold, for tem- 

 peratures of about 20° C. the tubes were immersed in cooled water. 

 For testing for sensations of warmth and hotness the tubes were 

 immersed in a Avater bath that almost completely covered the test 

 tubes. Irregular orders were folloAved in determining the temper- 

 ature sensations, and no indication Avas given the subject AA^hat the 

 next kind of stimulation Avas to be. Moreover, the same square cen- 

 timeter Avas never tested tAvice by the same stimulus in succession. 

 The tulx^s Avere allowed to rest on the skin for only one or two sec- 



