Acid-base Balance in Sweat

The reaction, the osmotic pressure, and the volume relationships of the body fluids are closely dependent on the properly regulated acid-base equilibrium. We have attempted to work out some of the regulatory mechanisms for the preservat.ion of acidbase equilibrium during the process of heavy sweating in ways analogous to those employed in the many similar studies of blood and urine. The changes to be recorded take place within a comparatively short space of time, so that we can study the factors for regulating acid-base balance without the interfering effects of the intake of food and the loss of catabohtes in the urine and feces (the subjects void minimal amounts of urine) ; also the compensatory mechanisms whereby the loss of fixed base is reduced to a minimum at a time when the body fluids are undergoing marked changes become apparent. It is extremely difficult by ordinary means to cause a substantial elevation of body temperature. We have therefore made use of the so called radiotherm. This machine produces a rapidly varying electrical field of a frequency of about 10 million cycles between the plates of a condenser. The body of the subject rests between the plates, but not in contact with them. The body is a poor dielectric and hence at such frequencies heat is produced. This heating is developed throughout the body, and there is no great temperature gradient at any point. In order to deliver heat at the same rate with ordinary methods of heating, a very great temperature gradient from the surface inward would be required, resulting necessarily in skin temperatures dangerous to the subject. The heating of the patients requires approximately 1 hour, as can be seen from the temperature curve (Fig. 1). After the