APPENDIX. 



the air, before it passes into the lungs of the rabbit, has to 

 traverse the syringe, it is necessarily warmed by the heat- 

 ed parietes. As it might have been stated that the air, 

 which was sent in, heated the animal to an inordinate extent, 

 I endeavoured to obviate such an objection by ascertain- 

 ing the temperature of the air during the whole process of 

 inflation. A wooden box, about the size of a walnut, was 

 made of two parts ; the bulb of a thermometer was placed 

 within, and when these parts were joined, the neck of the 

 instrument was firmly embraced. The box was after- 

 wards rendered perfectly air-tight by means of sealing- 

 wax. At each end of this box was a small brass tube, 

 one of which was connected, at pleasure, to the tube sol. 

 dered to the end of the syringe, and the other to the tube 

 inserted into the trachea of the animal. As the air passed 

 through the heated syringe into this box before it reach- 

 ed the lungs of the animal, the mercury was raised or de- 

 pressed according to the temperature of the medium to 

 which it was subjected. In this way it is easy to estimate 

 the temperature of the air which is sent in, and, by keep . 

 ing it many degrees beneath the heat of the system, we are 

 enabled to make the conditions of artificial inflation some- 

 what similar to those belonging to natural respiration. 

 Two wooden screens, separated by about four inches from 

 each other, intervened between the animal and tin box. 

 The machine was shown to Dr MILLIGAN, and he approv- 

 ed of the contrivance : It was also exhibited and explain- 

 ed by him to his Physiological Class in the Session of 

 1829- 



THE END. 



J-)hn Moir, Printer, Edinburgh. 



