RATE OF MOVEMENT OP THE BLOOD 211 



mouth under the tongue; whereas of course the temperature of the venous 

 blood, as already explained, is equal to the mean temperature of the 

 water during the time that the hand was immersed in it. Further de- 

 tails of the teehnic of this method will be found elsewhere, but it may be 

 said here that it is extremely simple and accurate, and that it requires 

 nothing more than (1) an accurate thermometer ranging between abo^ J 

 40 C. and 50 C., with a scale so drawn out that readings can be made 

 to Moo of a degree, and (2) a well-constructed vessel of about 3,000 

 c.c. capacity, with double walls, the space between them being packed 

 with some heat-insulating material such as ground cork. 



Results. Regarding the results obtained with these methods, it has 

 been found that the blood supply for each 100 grams of tissue in the 

 viscera, as measured by the stromuhr method, is about as follows: stomach, 

 21 c.c. ; intestine, 71 c.c.; spleen, 58 c.c.; liver, arterial, 25 c.c.; liver, 

 venous, 59 c.c.; liver, total, 84 c.c.; brain, 136 c.c.; kidney, 150 c.c.; thy- 

 roid gland, 560 c.c. The large blood supplies of the thyroid gland and 

 of the kidney are the most striking results of these observations. 



By the use of the calorimeter method the bloodflow through the hands 

 and feet of a healthy young man has been found to be about 13 grams 

 per 100 c.c. of hand per minute for the right hand, and about half a 

 gram less for the left. The footflow is only about one-third to one-half 

 that of the hand per 100 c.c. of tissue a difference which is largely 

 owing to the greater proportion of skin and the smaller proportion of 

 bone m the hand. The average footflow or handflow for a given indi- 

 vidual under ordinary conditions is remarkably constant from time to time, 

 but it is extraordinarily sensitive to changes in the temperature of the 

 environment in which the subject has been living for some time previous 

 to the measurement. In one individual, when the room temperature was 

 20 C., the flow in the right hand, expressed in grams of blood per 100 

 c.c. of hand or foot, was 10.1; when it was 22.8 C., the flow was 12.8; 

 when it was 25 C., 12.1 ; when it was 30 C., 18.5. On account of the 

 influence of temperature on the flow, it is extremely important that the 

 measurements should be made in a small room the temperature of which 

 is kept constant, or if it must be made in the wards, the bed should be sur- 

 rounded by curtains. The measurements made on the hands of dispensary 

 patients shortly after coming in from outside air are very likely to be 

 fallacious. The importance of making such bloodflow measurements in 

 the clinic will be alluded to later. 



Of course the measurements made by the above method in man tell us 

 only the rate of flow in the periphery of the body, and furnish us with no in- 

 formation regarding the flow of blood through the viscera. It is, how- 

 ever, a well-established fact that the bloodflow in the central part of the 



