PREFACE 



The study of bacteriology in technical schools of all kinds has 

 grown rapidly in the past few years, and especially in the institu- 

 tions which teach agriculture and allied subjects. The present 

 work is an attempt to outline a profitable course for students 

 in such classes. The Manual is the outgrowth of several years' 

 experience in teaching bacteriology to students of agriculture 

 and engineering, and includes some experiments which have not 

 previously appeared in print. 



The writer has tried to outline many experiments calling for 

 the simplest kind of equipment, but which should acquaint the 

 student with some fundamental facts concerning bacteria. In the 

 main, however, the Manual is devoted to more extended experi- 

 ments which call for precise results and need precise apparatus 

 for their performance. Wherever possible the experiments are 

 planned to give quantitative results, to the end that vagueness 

 of statement and uncertain thinking may disappear. 



In addition to the outhne for the study of bacteria, a section 

 has been added outlining the study of important fermentations 

 caused principally by fungi. In most cases the agricultural 

 student desires to become acquainted with the more fundamental 

 principles of the cultivation of these organisms. 



The appendixes are intended to present in a convenient form 

 both new and well-known methods. The section on sterilization is 

 designed to aid the advanced worker by supplementing the facts 

 given in the body of the Manual. Emphasis is placed upon 

 several facts recently brought out in investigations on sterilization. 



References to the literature bearing directly upon the subject 

 of the exercise have been introduced wherever possible. The 

 conspicuous position of these references is designed to stimulate 

 the student to do collateral reading. 



