Diurnal Curve of the Temperature of the Anamal Body. 551 
Thermo-couples, 7.¢., the electric thermometers employed, and the leads; 
(3) The Automatic Photographic Recorder, the author develops his method 
of continuous photographic registration, and he dwells particularly on the 
perfection of the arrangement of the thermostat which he has, with the help 
of Herr Fritz Koehler, the University Mechanician, of Leipzig, devised. He 
further discusses, at some length, the arrangements of the photographic 
recorder constructed for him by the Cambridge Scientific Instrument Com- 
pany, dwelling particularly on the optical arrangements which have been 
adopted, and which have resulted in an extraordinary clearness and sharpness 
of the curves furnished by the instrument. ? 
Discussing, in the next place, the method of quasi-continuous registration 
of the curve of the temperature of man, in which an ink-record is inscribed 
on a comparatively slowly rotating cylinder, the author describes “the 
thread recorder” of Mr. Horace Darwin, F.R.S., specially wound, and with a 
more than usually delicate suspension, as the special instrument for the 
record of the curve of the temperature of man for such clinical investigations 
as will be carried out in future in hospitals and sanatoria. 
The paper, which is one concerning methods of investigation rather than 
results, closes with some illustrations exhibiting the application both of the 
continuous and the quasi-continuous methods to the study of the temperature 
of the animal body. 
The result which comes out very strikingly, and for the first time, from 
these first applications of very exact and automatic methods to the study of 
the heat changes in the animal body, is that the temperature in any given 
area never remains constant during two consecutive minutes or fractions of a 
minute, in consequence, no doubt, of varying, and in some cases, perhaps, 
rhythmical, variations in the action of the great vaso-motor centre and the 
centres which are subordinated to or in relation with it. 
