ROUTINE OF AX EXPERIMENT WITH MAN. 97 



The stethoscope is attached as nearly as possible over the apex beat of 

 the heart by means of a light harness of canvas. In the use of the Bowles 

 stethoscope, it has been found that the heart-beats can easily be counted if 

 there is but one layer of clothing between the stethoscope and the skin. 

 Usually it is placed directly upon the undershirt of the subject. 



The pneumograph is placed about the body midway between the nipple 

 and the umbilicus and sufficient traction is put upon the chain or strap 

 which holds it in place to secure a good and clear movement of the tambour 

 for each respiration. 



The subject is then ready to enter the chamber and, after climbing the 

 stepladder, he descends into the opening of the chair calorimeter, sits in 

 the chair, and is then ready to take care of the material to be handed in to 

 him and adjust himself and his apparatus for the experiment. Usually 

 several bottles of drinking-water are deposited in the calorimeter in a 

 convenient position, as well as some urine bottles, reading matter, clinical 

 thermometer, note-book, etc. Before the cover is finally put in place, the 

 pneumograph is tested, stethoscope connections are tested to see if the 

 pulse can be heard, the rectal thermometer connections are tested, and the 

 telephone, call-bell, and electric light are all put in good working order. 

 When the subject has been weighed in the chair, the balance is tested to see 

 that it swings freely and has the maximum sensibility. All the adjustments 

 are so made that only the minimum exertion will be necessary on the part 

 of the subject after the experiment has once begun. 



SEALING IN THE COVER. 



The cover is put in place and wax is well crowded in between it and the 

 rim of the opening. The wax is preferably prepared in long rolls about the 

 size of a lead-pencil and 25 to 30 centimeters long. This is crowded into 

 place, a flat knife being used if necessary. An ordinary soldering-iron, 

 which has previously been moderately heated in a gas flame, is then used to 

 melt the wax into place. This process must be carried out with the utmost 

 care and caution, as the slightest pinhole through the wax will vitiate the 

 results. The sealing is examined carefully with an electric light and 

 preferably by two persons independently. After the sealing is assured, the 

 plugs connecting the thermal junctions and heating wires of the cover with 

 those of the remainder of the chamber are connected, the water-pipe is 

 put in place, and the unions well screwed together. After seeing that the 

 electrical connections can not in any way become short-circuited on either 

 the metal chamber or metal pipes, the asbestos cover is put in place. 



ROUTINE AT OBSERVER'S TABLE. 



Some time before the man enters the chamber, an electric lamp of from 

 16 to 24 candle-power (depending upon the size of the subject) is placed 

 inside of the chamber as a substitute for the man, and the cooling water- 



