«04 



SCIENCE 



[N. S. Vol. XXX. No. 779 



H. W. Daudt, M.S. (Harvard), assistant in 

 chemistry, and Miss Florence Balch, M.A. 

 (Columbia), instructor in mathematics. 



The following appointments have been made 

 in the School of Mining, Kingston, Ont. : 

 M. B. Baker, B.A., B.Sc, advanced from lec- 

 turer to professor of geology; Leo F. Gutt- 

 mann, Ph.D., assistant professor of chemistry; 

 R. J. Manning, M.A., lecturer on chemistry; 

 W. D. Bonner, M.A., lecturer on chemistry; 

 J. Eobertson, M.A., lecturer on physics ; G. H. 

 Herriot, B.Sc, lecturer on mathematics; S. N. 

 Graham, B.A., B.Sc, lecturer on mineralogy; 

 J. A. McCrae, M.A., M. L. Hersey fellow in 

 chemistry; B. Rose, B.Sc, assistant in min- 

 eralogy; B. E. Norrish, B.Sc, assistant in 

 drawing. 



The council of King's College, London, have 

 appointed Dr. David Waterston as professor of 

 anatomy, in succession to Professor Peter 

 Thompson, appointed professor of anatomy in 

 Birmingham University. Dr. Waterston was 

 lecturer in anatomy in the University of Edin- 

 burgh. Dr. George C. Low has been elected 

 lecturer in parasitology and medical ento- 

 mology. 



Mr. W. S. Abell, instructor in naval archi- 

 tecture at the Royal Naval College, Green- 

 wich, has been appointed to the chair of naval 

 architecture in Liverpool University, endowed 

 by Mr. Alexander Elder. 



Dk. E. von Tschermak has been appointed 

 professor at the Hochschiile fiir Bodenkultur, 

 Vienna. 



DISCUSSION AND COBRESPONDENCE 



THE EFFECTS OF RAPID AND PROLONGED DEEP 

 BREATHING 



The following results of simple experiments 

 may be of sufficient general interest to war- 

 rant publication in the columns of Science. 

 They are in no sense new, but are described 

 by way of emphasizing important facts which 

 have been generally neglected and not with 

 any pretense to originality. 



The experimental results to which I refer 

 show the effect of enforced deep breathing 



over a period of several minutes on various 

 functions of the human body. These effects 

 are of several kinds and a few of the simpler 

 ones may be summed up as follows: (1) ma- 

 terial increase in the length of time the system 

 can do without respiration; (2) effective men- 

 tal stimulant; (3) material increase in phys- 

 ical endurance for a short time; (4) rise in 

 the frequency of pulse beat. 



1. It has been noticed by others that deep 

 violent breathing for several minutes so 

 changes the system as to make respiration 

 unnecessary for perhaps as much as five min- 

 utes after this preparatory breathing is over. 

 In my own case I have found that four min- 

 utes' enforced breathing makes it possible to 

 hold the breath for three minutes and a half, 

 whereas without this preparation 56 seconds 

 was my limit. The time during which it is 

 possible to do without respiration increases, 

 of course, with the length of time during 

 which the preparatory breathing is carried on. 

 The increase does not go on indefinitely, but 

 reaches a definite limit, beyond which further 

 length of time given to preparatory breathing 

 does not increase the time during which the 

 breath may be held. Below is a table taken 

 from a curve which represents experiments 

 on myself. The limit (3 minutes 34 seconds) 



(a) Length of time in minutes devoted to deep 



breathing. 

 (6) Time in minutes and seconds during which 



the breath may be held after preliminary 



breathing is stopped. 

 («.) i J 4 1 2 3 4 

 (6) 0.56 1.24 1.39 1.54 2.12 3.00 3.26 3.34 



which is indicated in this table would doubt- 

 less differ with different people. It should be 

 noticed that the preparatory breathing is ef- 

 fective long after the " washing out " of the 

 lungs must have been completed. The change 

 produced in the system is certainly, therefore, 

 more fundamental than a lung change, and 

 would appear to a layman to indicate a tem- 

 porary change in blood constitution. 



2. The effect as a mental stimulant is very 

 pronounced. I have noticed in my own case 

 that mental fatigue may be postponed, far 

 beyond the usual point, by two minutes of 



