Scientific Proceedings. 



45 



quantity was taken in each experiment at regular intervals, vary- 

 ing from fifteen minutes to two hours until death ensued. In one 

 experiment a continuous fatal hemorrhage was effected and the 

 blood analyzed in portions. Thus far twenty experiments have 

 been carried out. In some of them the serum was also analyzed. 



The following conclusions were reported : Hemorrhage causes 

 increase of water and decrease of solids in the remaining blood. 

 Hemorrhages of about 0.6 Jo of body-weight, cause little or no change 

 in general composition of the blood until after 2.5 fo has been taken. 

 Under the conditions of these experiments it was generally found 

 that the longer the intervals between withdrawals the less the 

 maximal differences between composition of the first and last frac- 

 tions. Short intervals between bleedings, all other conditions being 

 equal, favored the largest total withdrawals before death ensued. 



The differences in the serum ran parallel with those in the 

 blood, but were less marked. The ash did not vary materially 

 in either the blood or serum, no matter how much blood was 

 taken. The blood ash and that from the serum were practically 

 the same in relative amount, though different in composition. 



When small quantities of blood, equal to about 0.2 fo of body- 

 weight, were removed at intervals of about a half-hour, little 

 change was noted in either blood or serum until after 3 Jo had 

 been taken. After this quantity had been lost the changes fol- 

 lowing further hemorrhage were such as usually occur. 



The maximum differences between the percentage composition 

 of the first and last fractions varied somewhat. The differences in 

 the amounts of solids, for example, ranged from 1.5 fo to 3.5 fo. 

 In fasting animals the influence of hemorrhage on chemical change 

 in the remaining blood was somewhat more marked than in well 

 nourished ones. The effect on the serum was about the same. 



Other influences in the experiments were carefully controlled. 

 The observed effects were due only in slight degree to the nar- 

 cotics and the conditions attending the operations. 

 44. « Demonstration of a new portable sphygmomanometer " : 



THEODORE C. J ANEW AY. 



The author's instrument was designed with the object of 

 securing a thoroughly portable clinical sphygmomanometer, in 

 which nothing essential to accuracy should be sacrificed. It em- 



