MICRO-ORGANISMS 



AND 



FERMENTATION. 



CHAPTEE I. 

 Microscopical and Physiological Examination. 



1. MICROSCOPICAL PREPARATIONS, STAINING, AND 

 MICRO-CHEMICAL EXAMINATION. 



THE Microscope will be for all time of paramount aid in the 

 investigation of micro-organisms, since these, as individuals, 

 are almost always invisible to the naked eye. The earliest 

 important observations in the physiology of fermentation we 

 owe to purely microscopical investigations, and it was not 

 until the last decades that biological and physiological 

 investigations were undertaken. After a certain probability 

 had arisen that the same species of micro-organism did not 

 always occur in the same form, work was eagerly commenced 

 in different laboratories with so-called " culture experiments," 

 in which attempts were made, by conditions of growth 

 artificially brought about, to observe the different phases of 

 development in one and the same spot, in order to thus 

 determine the entire process of development. The idea was 

 correct, but the way in which it was worked out was at that 

 time so faulty that " culture experiments " threatened in 

 consequence to fall into utter disrepute. The work was carried 

 out without any proper precautions, as the following example 

 shows. Beer yeast was sown on a moist slice of bread ; the 



