Franz, Sensations folloiun^g Nerve Division. 109 



point of a pin apart from tlie pain of the prick (acuesthesia) ; dis- 

 crimination of intermediate degrees of temperature, from about 

 25^ C. to about 40" C. 



''Loss of pi'otopathic sens'iblUti) abolishes: cutaneous pain, espe- 

 cially that produced by pricking, burning, or freezing, together with 

 that of stimulation , with the painful interrupted current; over hair- 

 clad jiarts, plucking the hairs ceases to be painful ; sensations of 

 heat from temperature above 45 ° C. ; sensations of cold from tem- 

 peratures below 20° 0. 



"After destruction of all cutaneous aft'ercnc iil)ers the part is still 

 endowed with deep sensibility, pressure can be recognized, and its 

 gradual increases appreciated ; pain is produced by excessive pres- 

 sure (measured by the algometer) ; movements of muscles can be 

 recognized ; the point of application of pressure can be localized ; the 

 patient can recognize the extent and direction of movement produced 

 passively in all joints within the affected area."^ 



It will be seen, therefore, that the examination of patients in 

 whom nerves have been injured or cut reveals many different degrees 

 or qualities of sensation in addition to the four which, from the 

 examination of normal individuals alone, have been supposed to be 

 the only sensory elements. The main points of difference between 

 the old and the new view — so far as the enumeration of sensations 

 is concerned — are as follows: There is apparently a difference 

 between the sensations of hot and warm, and between those of cold 

 and cool ; touch is different from pressure ; there are different kinds 

 of j)ain. 



When, for example, the ulnar nerve has been cut, examination 

 of the skin with various stimulating objects shows that over the 

 hairless portions of the fourth and ring fingers light touches with 

 a wisp of cotton wood or with a fine camel's-hair brush are not felt ; 

 the hair-clad parts may or may not react to such stimuli, depending 

 upon the location of the lesion; parts of these fingers will not be 

 sensitive to temperature stimuli, and perhaps not to pressure ; there 

 may, or may not, be sensations from pricks of a pin ; and if the 



^Ileacl and Tlionipson : The Grouping of Afferent InLpnlses within the Spinal 

 Cord. Brain, 1900, Vol. 29, p. 551. 



