PREFACE. 



A BRANCH of study, which has opened fresh 

 paths in pathology and therapeutics, is so 

 important that it may in time become a more 

 essential part of the medical curriculum, and is 

 perhaps worthy of an elementary handbook, which 

 shall include a systematic sketch of the genera and 

 species of micro-organisms, as well as the methods 

 employed in the investigation of their life-histories. 



Having myself experienced the want of a practical 

 aid to the study of Bacteriology by the methods 

 introduced by Professor Koch, I thought that it 

 might be useful to those wishing to commence this 

 study by these recent methods, if I embodied my 

 notes made in different laboratories in the form of a 

 Manual for Students. The work is thus intended 

 to help the student beginning the study of a subject, 

 the literature of which, in English, is for the most 

 part diffused in numerous periodicals. 



The methods of "pure cultivation " of Bacteria 

 will, after all, be found to be remarkable for their 

 extreme simplicity, and can be easily mastered by 



