Apparatus and Methods for Micro-Incineration

Abstract

In this article micro-incineration and the necessary apparatus is considered. This in itself is but the first step in determining the mineral content of cells, tissues and organs; but it is a very necessary step as by it one can compare the position and different amounts of ash in individual cells, and in different parts of tissues and organs. In 1833 Raspail, founder of chemical microscopy, showed that me original appearance of even the finest detail is represented in the ashes. The present paper describes the electric furnace originated by the histologist Policard, explains the method of preparation and sectioning objects for incineration, and finally the process itself. The microscopic outfit needed for the study is also described. This consists of an ordinary microscope with an Abbé or aplanatic substage condenser with central dark-stops, of 10, 15 and 20 mm., for the different objectives. These range from 16 mm. to oil immersions, the powers above 16 mm. having iris diaphragms to reduce the aperture a suitable amount. It is further shown that there is great advantage in having some sections of an object incinerated and neighboring sections stained and mounted for comparison. The incinerated preparations are to be studied with the dark-field and the stained ones with the bright-field microscope, the two instruments close together so that the observer can look from one to the other. Finally, there is given the method of calibrating the electric furnace so that one may know the temperature at each step in the incineration. There is also a short bibliography of some important publications with brief annotations as to their special significance.