PREFACE. 
BACTERIOLOGY is essentially a laboratory study. 
It is only by actual laboratory work that it can be 
taught in such a manner as to serve any useful pur- 
pose. It is also a subject of very general scientific 
interest. Courses in bacteriology are no longer con- 
fined to the medical schools, but are being intro- 
duced into colleges and agricultural and industrial 
schools. ‘This volume has been prepared as a guide 
to the practical details of laboratory work. It is 
intended to present the subject in such a general 
way as to lay a broad foundation for later specializa- 
tion in any branch of bacteriology. By a judicious 
selection the course can be made to conform to the 
requirements of medical, agricultural, or industrial 
students. 
Brown UNIVERSITY, August, 1901. 
