6 MICRO-ORGANISMS AND FERMENTATION. 



certain staining reagents employed (as, for instance, hsema- 

 toxylin solution). 



'2. BIOLOGICAL RESEARCH BY MEANS OF THE MICROSCOPE ; 

 MOIST CHAMBERS. 



A true and thorough insight into the nature of the organ- 

 isms of fermentation is not attainable until the method of 

 biological and physiological investigation is resorted to. As 

 stated above, endeavours were made long ago to devise methods 

 of this nature ; the entire neglect of precautions in carrying 

 out the experiments resulted, however, in complete failure, and 

 a reaction then set in, which found expression, e.g., in the work 

 of EEESS on the Saccharomycetes (1870), in which he 

 expressly stated that he had taken no precautions to obtain 

 pure cultures, to such a degree had these cultures fallen into 

 disrepute. In the course of the following years, however, these 

 methods were adopted under happier auspices, and microbiology 

 has now reached a high degree of development. It is, perhaps, 

 an almost unique fact in the history of science, that, in so 

 short a time, a new method of investigation has not only been 

 adopted, but has also yielded practical results, both in patho- 

 logical science and in our own special branch, results which 

 have brought about a revolution in many previously accepted 

 doctrines. 



The aim of biological and physiological investigations of 

 micro-organisms is to gain an insight into their development 

 and vital functions. The means to be employed in order to 

 attain such an insight are, naturally, to determine such con- 

 ditions for their growth and propagation as to make it possible 

 to observe the changes gradually taking place in the organism 

 itself and in the substances influenced by it. When the object 

 aimed at is solely to obtain a knowledge of the various forms 

 which the organism assumes during its development, the con- 

 ditions are much more easily attained than when a culture on 

 a large scale is attempted. Such a culture of individuals 

 originating from one cell of the species is required for the 

 purpose of gaining an insight, through physiological, chemical, 

 or purely practical experiments with larger quantities of these 



