Scientific Proceedings. 



i5 



Second meeting. 1 



Physiological Laboratory of New York University and Bellevtie 

 Hospital Medical College. April 15, ipoj. 



5. " Changes in the blood-volume of the vein of the sub- 

 maxillary gland on stimulation of the chorda tympani 

 and sympathetic nerves," with demonstrations of curves : 

 RUSSELL BURTON-OPITZ. 



The author explained the mechanism of a recording stromuhr 

 by means of which he made quantitative determinations of the 

 blood-flow in the vein conveying the blood from the submaxillary 

 gland. The blood-volume was measured previous to, as well as 

 during, the stimulation of the secretory nerves. The curves which 

 were exhibited showed very striking changes in the blood-flow, 

 namely, an increase on stimulation of the chorda and a decrease 

 when the current was applied to the sympathetic fibers. In the 

 former case the volume of the blood-flow (c.c. per second) was 

 from about two to nearly six times as great as normal, and in 

 the latter case it was from about one-half to one-fifth the normal 

 volume. By using a strong stimulus a complete cessation of flow 

 can be produced. 



6. " Does a backward flow ever occur in the veins ? " : RUS- 

 SELL BURTON-OPITZ. 



The results of this investigation may be summarized as fol- 

 lows : A backward swaying of the column of blood in the central 

 veins is a constant normal phenomenon. It is produced by two 

 factors : first, by the contraction of the right side of the heart ; 

 and second, by high intrathoracic pressure (forced expiration). 

 If the distal conditions in the venous system are favorable, this 

 backward movement can also be obtained in the peripheral veins 

 (femoral veins). The same instrument was used in this investiga- 

 tion as in the former. 



7. "A new method of studying metabolism": GARY N. 

 CALKINS. 



The author described experiments then in progress upon metab- 

 olism in unicellular animal organisms. These forms, reproduc- 



1 Reprinted from Science, 1903, xvii, p. 741 and American Medicine, 1903, v, p. 



708. 



