Control of Respiratory Movements. 55 



140 (1318) 



Amylase and protease action of some pancreas preparations. 

 By H. C. Sherman and Dora E. Neun. 



[From the Laboratory of Food Chemistry, Columbia University.] 



It was shown that the purified preparations of pancreatic 

 amylase always exhibit a marked proteolytic activity whether 

 tested by determination of total nitrogen of digestion products, 

 by determination of amino nitrogen, by the Van Slyke method, 

 by determination of acidity of digestion, or by the increase of 

 electrical conduction. 



While fractional precipitation by alcohol yields a first precipi- 

 tate of increased proteolytic activity, the other (more soluble) 

 fraction shows no increase in amylolytic power over the usual 

 purified amylase preparation, and only a slight decrease of proteo- 

 lytic power. The problem of the relationship of the amylolytic 

 and proteolytic activities of these preparations was discussed. 



The investigation was carried out with the aid of a grant 

 from the Carnegie Institution of Washington. 



141 (1319) 



The role of afferent impulses in the control of respiratory move- 

 ments. 



By Helen C. Coombs and F. H. Pike. 



[From the Department of Physiology of Columbia University.] 



As the result of further experimentation, we wish to add to a 

 previous statement (American Journal of Physiology, 1917, XLII, 

 P- 395) the following facts : 



1. The movements of the ribs, which cease after division of 

 the dorsal roots of the spinal nerves in the thoracic and cervical 

 regions, are resumed when the phrenics are divided. 



2. The respiratory movements become labored when the vagi 

 are divided in the neck after these procedures, and soon cease. 

 The effects of vagotomy are more severe if the dorsal roots of the 



