of two concentrically arranged copper cylinders, the outer one being about one-third greater in diameter, thus creating a second annular chamber between the two, which is filled with water for the purpose of maintaining a uniform level of temperature to the calorimeter. Through the inner chamber the air is drawn over the animal, and pumped out through the large metre of 'Voit's respiration apparatus by a water-wheel attachment. The D'Arsonval gas-regulator I will not describe, since it never worked satisfactorily and was not used in any of my experiments. The thermometric observations were made on Geissler's thermometers, which were previously carefully tested at the Yale Observatory and the necessary corrections made. I will exemplify these experiments by rendering the first one in detail, and in the succeeding ones simply make use of the results obtained. The method of calculation employed in these experiments is practically the same as that of Dr. H. C. Wood. Experiment 3.- Rabbit; weight, 3.26 pounds. 75.110 71.360 Time. P.M. Rec. temp. Cal. temp. 1.24 2.24 104.4° 104.6° 69.25° 69.55° .30° 2.40 .045 gramme of antifebrin injected hypo dermically. Time. Rec. temp. Cal. temp. P.M. 3.06 4.06 71.360 .80° gain. .30° gain corrected.* 3.75° loss. 2 40.045 gramme antifebrin injected hypodermically. Time. Air Exit. Cal. R. temp. Metre. P.M. temp. temp. temp. 3.06 75 35° 70.930 70.350 105.00 869100 3.21 75.050 73-45° 70.750 3.36 74.950 73.81° 70.950 3-51 74 750 73.090 71.150 4.06 74.550 73.090 71.350 104.40 870629 74.930 72.87° 70.910 .6° loss. 1529 72.870 1.000 gain. .64° gain corrected. 2.060 loss. * By making a series of experiments in which there was no animal placed in the chamber of the calorimeter, and no air pumped through, it was observed that the calorimeter temperature in one hour rose .09o for every degree that the air temperature stood above that of the calorimeter; discovering the fact that the calorimeter rise was due to three factors instead of two, viz., heat given to the calorimeter by the animal, heat given off by the air passing through (always at a temperature about 3o higher than that of the calorimeter), together with a relatively large amount of heat taken from the surrounding air. This last factor was always overcome by making this.09 correction on the calorimeter gain previous to the calculation of heat units given to the calorimeter. Gain in heat dissipation. 24.72 14.30 Hourly heat production before antifebrin........... 10.96 12.14 Time. Hourly heat production before antifebrin....... Hourly heat production after antifebrin..... 10.96 10.19 Loss in heat production........... Experiment 6.-Rabbit; weight, 2.74 pounds. -77 Rec. temp. P.M. 1.37 102.4° 2.37 102.2° Cal. temp. 66.59° 67.14° .55° 3.02.0075 gramme antifebrin injected hypo dermically. Time. Rec. temp. P.M. 1.27 101° 2.27 101° Cal. temp. Time. 68.85° Rec. temp. PM. 69.24° 3.32 102.8° 4.32 102.0° .39° 2.59.015 gramme injected hypodermically. Cal. temp. 67.79° .60° 4.50 .045 gramme injected into jugular vein. Table No. 1.-Antifebrin Experiments on Normal Animals. To better compare the results obtained in the foregoing experiments I have tabulated them as follows: The plus and minus signs in the first column indicate respectively increase and decrease of heat dissipation and heat production. The same signs after the heat units expressed indicate (relatively) large and small doses. Examination of the results as exhibited in Table 2 shows an increase of heat dissipation in seven of the nine experiments and a decrease of heat production in five. The only deduction that can be made is evident in the table itself, viz., that the antipyretic action of antifebrin is due principally to an increase in heat dissipation aided in more than half the cases by a decrease in the production. Also that, relatively speaking, both large and small doses increase heat dissipation, while as to heat production large doses seem to increase and small doses to diminish it. 2.25 2.34 2.35.15 47 114 2.37 2.40.15 53 104 2.47 2.50 2.51 Struggling. 2.55 Struggling. Upon examination of the above plate where we have the curves of heat production and heat dissipation so placed as to show their relation to one another, and also to the dose and temperature, it will be observed that an alteration in the normal relation of heat dissipation and heat production occurs in Experiments 5, 6, and 8, where there is an increase of dissipation occurring synchronously with a decrease of heat production instead of a corresponding 3.15 increase in heat production, since in health increased heat dissipation provokes increased heat production and decreased dissipation decreased production; while, on the other hand, increased heat production is always attended by increased dissipation, and vice versa, thus keeping the bodily temperature uniform. The following experiments were then made to note the relation existing between the temperature and the pulse after the administration of the drug. PLATE I.-The dotted line shows heat dissipation and the straight line heat production; the curves above and below the zero line, which is the normal line, mean so many units of increase or decrease of heat production or heat dissipation after the use of the drug. The dose curve is at the bottom of the plate, while the temperature curve is at the top. Thus, in Experiment 9, the dose is 06 gramme, heat production and heat dissipation are diminished, and the temperature rose from 102.2° to 102.40. |