292 CARNEGIE INSTITUTION OF WASHINGTON. 



study any broncho-constrictor or broncho-dilator effects of the drug 

 from the volume of the dead space of breathing in the individual experi- 

 ments and also supplied data as to variations in the gaseous metabolism 

 due to the drug. 



The influence of alcohol on sense thresholds. — With the development of 

 further accurate techniques for studying the sense thresholds, this 

 phase of the alcohol research can now be entered into profitably. The 

 investigation undertaken by Professor Miles is a completion and elabo- 

 ration of section I of the psychological part of the "Tentative plan for 

 a proposed investigation into the physiological action of ethyl alcohol 

 in man." 



Respiration in oxygen-rich atmospheres. — In many of the forms of 

 respiration apparatus used in this Laboratory, the percentage of oxygen 

 in the air inspired by the animal is rarely that of normal air. This fact 

 has led to an extended investigation on the influence of the inhalation 

 of atmospheres rich in oxygen. The effect upon human subjects has 

 been extensively studied in short experiments by Mr. Higgins, of the 

 Laboratory staff, and no material alteration has been found in the total 

 amount of oxygen absorbed or carbon dioxide produced, even when an 

 atmosphere containing 95 per cent of oxygen has been inhaled for 

 periods of 15 minutes. As it is obviously impossible to use human 

 subjects for very long periods, a series of experiments has been carried 

 out with rabbits, employing a special form of respiration apparatus and 

 chamber, the preliminary experiments being made in association with 

 Dr. Carl Tigerstedt. This research has been steadily continued 

 throughout the experimental year with the active cooperation of Pro- 

 fessor Howard T. Karsner, of the Harvard Medical School, whose 

 studies of the subjects, after a long sojourn in the oxygen-rich atmos- 

 phere, lend great value to the research. In these experiments the 

 rabbit is placed inside the chamber in an atmosphere which is main- 

 tained at a high percentage of oxygen for several days; the rabbit is 

 then killed and a complete study of all its tissues made. The results 

 should throw much light upon the clinical use of oxygen. 



Insensible perspiration and muscular activity of infants. — In conjunc- 

 tion with Dr. H. W. Stevens, of the Massachusetts General Hospital, 

 and Dr. Fritz B. Talbot, a series of observations was made upon the 

 insensible perspiration of infants. A simultaneous graphic record of 

 the muscular activity of the infant was likewise made by means of a 

 modified form of the so-called 'Svard crib recorder." With this appa- 

 ratus, the infant lies in a crib suspended at one end on a knife-edge and 

 at the other by a stout spring; the vertical movements of the crib due to 

 the muscular activity of the child are summed up by a work-adder 

 arrangement and the total effective movement for a given period of 12 

 to 24 hours is thereby recorded. Wlien the sum of muscular activity 

 is compared with the actual loss in weight of the infant due to insensible 

 perspiration, an interesting relationship may be established. 



