General physiology; an outline of the science of life . d by greater activity of the cells of a tissue, , a gland ora muscle, than by less activity or during rest. This result is inclose accord with our ideas concerning the production of heat, forthe greater activity of the cells depends upon a greater metabolismin them, and heat results from chemical transformations in the is an old experience that one can warm himself by vigorousmuscular activity. s 2 260 GENERAL PHYSIOLOGY All measurements of temperature, whether by the thermometeror the thermo-electric method, serve only to det
General physiology; an outline of the science of life . d by greater activity of the cells of a tissue, , a gland ora muscle, than by less activity or during rest. This result is inclose accord with our ideas concerning the production of heat, forthe greater activity of the cells depends upon a greater metabolismin them, and heat results from chemical transformations in the is an old experience that one can warm himself by vigorousmuscular activity. s 2 260 GENERAL PHYSIOLOGY All measurements of temperature, whether by the thermometeror the thermo-electric method, serve only to determine thetemperature that prevails in some one place in the organism atsome one time. They give no particulars regarding the quantityof heat that the organism or the individual tissue produces. Butit is possible to determine the quantity of heat by investing thenumber of heat-units, or calories, that the living body gives offto the outside in a certain time. Thus calorimetry has developedby the side of thermometry. As is well known, a calorie is that. Fig. 116 a.—Mirror galvanometer. Upon a board is an upright, supported by two columns ; theupper portion consists of a glass tube in which hangs a silk fibre suspending a ring-magnetin the lower portion. At the two sides are two coils of wire. (After Cyon.) quantity of heat that is necessary to warm one kilogram of waterfrom 0° C. to 1° C. In order to measure the number of caloriesthat a living body, for example an animal, produces in a definitetime, the water-calorimeter has been constructed (Fig. 117). Thisconsists of a box having double walls that may be closed upon allsides. The space between the two walls is filled with water, theanimal is placed in the box, and the whole is protected fromcooling or warming from the outside by a non-conducting heat produced by the animal is communicated to the water ELEMENTARY VITAL PHENOMENA 261 and raises its temperature; the latter can be read off upon athermometer projec
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