An Indirect Calorimeter for the Determination of O2 and CO2.

Abstract

AND co, 925 W e have used a Vreeland oscillator, giving a current of pure sine wave form with no direct current component, the frequency of which can be changed by small gradations between 7000 and 300 cycles per second. Since the time of stimulation is one-half of a cycle, the minimum time of stimulation may be determined, our results on the stimulation of gastrocnemius muscle of the frog in Ringer's fluid being 0.000079 seconds. With curarized muscle it was found that the minimum time for stimulation was increased to 0.00009 seconds. The tongue muscle required 0.00013 seconds. The minimal time for stimulation of smooth muscle could not be determined by means of the oscillator because a low enough frequency could not be obtained, but this presents no difficulty since Englemann was able to determine it in 1870. This is a preliminary report. 3640An Indirect Calorimeter for the Determination ,of 0, and CO,.