Volume 1

Handbook for the physiological laboratory / by E.E. Klein, J. Burdon-Sanderson, M. Foster, and T.L. Brunton ; edited by J. Burdon-Sanderson.

  • Klein, E. (Edward) 1844-1925.
Date:
1873
Catalogue details

Licence: Public Domain Mark

Credit: Handbook for the physiological laboratory / by E.E. Klein, J. Burdon-Sanderson, M. Foster, and T.L. Brunton ; edited by J. Burdon-Sanderson. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

    23/628 (page 7)
    to employ higher temperatures, or to measure the temperature with greater exactitude, it is necessary to have recourse to Strieker's warm stage. Strieker's Warm Stage.—Of this there are two forms. In one the mode of heating, and consequently of modifying the amount of heat communicated, is that which has been already described (see Fig. 2). From its simplicity it is well adapted for the beginner, while it enables the more practised observer to main- tain any desired temperature within very inconsiderable limits of variation. The other, in addition to the greater exactitude which can be attained, has the advantage that, by its aid, it is possible to continue the observation for a very long period. It is this which is employed by Sanderson and Strieker for the study of the circulation in mammalia. F^or our present purpose we do not require the whole apparatus, so that it is only neces- sary to refer to those parts of it which are shown in Fig. 3. In the employment of this apparatus several difficulties are encountered. For instance, the temperature of the water recep- tacle is only in part controlled by the regulator. Then, again, the temperature of the stage is subject to variation according to the rate at which the water flows into and escapes from it; so that, if great care be not taken in the adjustment, constancy cannot be relied on. Another practical difficulty lies in the fact that the temperature of the water in the receptacle is different from that in (he stage, the rate of flow being so inconsiderable that there is necessarily a great loss of heat by radiation from the metal surface. If the stage be not fitted with a thermometer, this difference of temperature may be determined, once for all, by comparative measurements, so that the true temperature of the stage can then be known at any time by deducting the ascertained loss of heat, i.e., the ascertained difference above referred to, from the temperature to which the regulator is adjusted. Mfethod of varying the temperature rapidly.—In connec- tion with this apparatus, it is convenient to describe the method employed for subjecting a preparation to sudden alterations of temperature. With this view the following contrivance is used : —A clip is placed on the tube leading from the water receptacle (C, Fig. 3), by means of which the access of warm water to the stage may be interrupted. The end of the escape-tube (D) is then allowed to dip into a vessel of cold water. This done, cold water may be readily introduced into the stage, so as to cool it suddenly, by suction through the tube [C], which must be pro- vided with a branch (not shown in the figure) between the clip and the stage, for the purpose. This, of course, at once lowers the temperature. To effect a sudden rise, all that is necessary