1 8 85 .J 
54i 
Non-sensitive Points of the Skin. 
the skin which subserve the sense of touch. The feeling 
w ich arises , on irritating a temperature-point differs in 
strength at different points, and these require for their ex- 
citement a different degree of irritation. 
A noteworthy property of the temperature-points is that 
a se ^ sat [ on of temperature can be induced in them by a 
gentle thrust with a needle or a pointed splinter of wood. 
It appears therefore that the temperature-point is a very 
well-defined anatomical point, since the sensation of tem- 
peiatuie ensues only when the point is most accurately hit. 
In. like manner the feeling of temperature proper to these 
points can be excited by means of induction-currents. On 
t ie other hand, it is found that the temperature-points 
lecognise neither contact nor pain. The latter phenomenon 
ls very distinctly demonstrated by means of a fine needle 
which is plunged vertically into the skin. Here also is to be 
noted the sharp limitation of the temperature-point. 
If theie aie special nerves for the recognition of temper- 
atuie, we must naturally expeCt that they will, so to speak, 
tianslate every sensation into the language of temperature, 
just as a blow on the eye is perceived as a flash of light' 
and pressure on the nerves of hearing is felt as a humming 
noise. & 
The faCt that the temperature-points are insensible to pain 
reminds us of one of the. traditions of witchcraft. Amono- 
the methods of recognising a witch it was customary to 
thrust pins or needles into different parts of the body. 
Witches, it was thought, had certain spots insensible to 
pain,. and if the prick of a needle in any part was not felt 
the victim was at once condemned. In virtue of Dr. Gold- 
scheidei s researches we may say that these non-sensitive 
spots were simply the temperature-points, and that they 
would be found in all persons alike. 
T. hese expeiimental lesults permit the conclusion that the 
temperature-points present gaps in the sensitive field of the 
suiface of the skin, filled up, on the one hand, with specific 
cold-nerves, and on the other with heat-nerves. Thus, as 
far as the nerves of temperature are concerned, the doCtrine 
promulgated by Prof, von Helmholtz, that every nerve-fibre 
is capable of one only state of excitement, and consequently 
of only one quality of sensation, is fully confirmed. This 
view is further confirmed by the faCt that Dr. Goldscheider 
has succeeded, by eleCtrising the nerve-stems, in exciting 
very distinct peripheric sensations in the region of the 
nerves concerned,— the feeling of cold predominating, . The 
