430 TEMPERATURE TOPOGRAPHY. 



difference of temperature of the two needles or couples. In place of a single pair 

 of needles several may be used, whereby the sensitiveness of the apparatus is 

 greatly increased. Helmholtz found that by using 1C antimony-bismuth couples, 

 he could detect an increase of 40 1 00 C. Schiffer prepared a simple thermopile 

 (IV) by soldering together alternately four pairs of wires of iron (/) and German 

 silver (a). These are placed in the two organs (A and B), which are to be 

 investigated, whereby a very high degree of exactness is obtained. 



209. Temperature Topography. 



Although the blood, in virtue of its continual motion, completing, 

 as it does, the circulation in 23 seconds, must exercise a very consider- 

 able influence on the equilibration of the temperature in different 

 organs, nevertheless a completely uniform temperature does not exist, 

 and the temperature varies in different parts: 



1. Temperature of the Skin. 



Middle of the sole of the foot, . 32-26C. ) 



Near tendo achillis, . . 33 - 85 I J. Davy made these observations 



Anterior surface of leg, . 33 '05 I directly after standing, while 



Middle of calf, . . 33 '85 \ naked, with the temperature 



Bend of knee, . . 35 "00 / of the room at 21 C. Only the 



Middle of upper arm, . . . 34'40 I under surface of the ther- 

 Inguinal fold, . . . 35'SO 1 mometer touched the skin. 



Near cardiac impulse, . . 34 '40 J 



In the closed axilla, 36'49 (mean of 505 individuals); 36'5 to 37 '25 ( Wunderlich) ; 



36'89C (Liebermeister). 



The temperature of the skin of the head is higher in the region of the forehead 

 and parietal region than in the occipital region; the left side is warmer than the 

 right (Maragliano). Dyspnoea increases the temperature of the skin (Heidenhain, 

 Friinkel). 



Method. Liebermeister determines the temperature of free cutaneous surfaces 

 thus: The bulb of the thermometer is heated slightly above the temperature 

 expected; after the mercury begins to fall, the bulb is placed on the skin, and if 

 the bulb has the same temperature as the skin, the mercury remains stationary. 

 This experiment must be repeated several times. 



2. Temperature of the Cavities. 



Mouth under the tongue, . . . 37'19C. 



Rectum, ... 38 '01 



Vagina, 38'30 



(Uterine cavity somewhat warmer; cervical canal somewhat cooler.) 

 Urine, 37'03 



The temperature falls in the stomach during digestion (p. 332). 

 Cold injections (11C.) into the rectum rapidly lowe rthe temperature 

 in the stomach 1C. (Winternitz). 



3. The Temperature of the Blood is, as a mean, 39C. The venous 

 blood in internal viscera is warmer than the arterial, but it is cooler in 

 peripheral parts: 



