VI PREFACE 



trouble on the part of the lecturer, and finds only partial 

 favour with the student. 



We have therefore ventured to collect and put together 

 the slips and notes in the form and shape of a small hand- 

 book, which, though originally intended for use at the 

 laboratories of St. Bartholomew's Hospital, we hope may 

 supply a want felt elsewhere. The work is divided into 

 Lessons, and the book is arranged in three parts, of which 

 Parts I. and II. (Elementary Bacteriology and Bacteriologi- 

 cal Analysis) encompass three months' work, as required 

 for the Diploma of Public Health at London and Cambridge. 

 Naturally, we have adhered to our own system of teaching, 

 which represents that used for some years at the Pathologi- 

 cal Laboratories of Cambridge University and St. Bartholo- 

 mew's Hospital. A few explanatory remarks, therefore, 

 appear necessary. 



At St. Bartholomew's Hospital we invariably begin with 

 an Elementary Course (Part I.), which extends over five to 

 six weeks (three lessons a week). All media are supplied, 

 so that the simpler methods of work, inoculations, cultiva- 

 tions, staining, etc., may be quickly acquired and the 

 student may become acquainted with the general principles. 

 The rest of the term is then devoted to Bacteriological 

 Analysis (Part II), which includes the preparation of the 

 various media, and the analysis of air, water, food, etc., 

 the examination of filters, disinfectants, etc. As far as 

 possible we have given full directions, but these Lessons 

 are not intended to supplant the demonstrator, nor do 



