DEPARTMENT REPORTS. 47 



open into another line of bacter-ial studies, AvUicli doubtless will give 

 rich harvests. In fact, there is much to be placed to the credit of this 

 line of work at the present time. 



No field, however, otfers as much promise and has given such availa- 

 ble information as that which is to be gained from a study of the 

 tubercules found upon the roots of legumes. It is of great importance 

 that we know the functions of these tubercles which are filled with 

 bacteria, and, further, that their instrumentality in abstracting nitro- 

 gen ft'om the air be understood. Chemists ten years ago were constantly 

 teaching that the nitrogen Avould soon be exhausted in the soil and 

 that there were very few agents which contributed any, and what these 

 agents did contribute was in such small quantities as to be of little 

 use. We looked forward to nitrogen starvation. This is a good illus- 

 tration of the errors which creep into conclusions drawn from a study 

 of chemical elements and compounds without a study of those living 

 agents which are constantly manipulating them. Already the practical 

 application of this fact that tubercles will form on certain plants and 

 feed them with nitrogen has become extensive, and we look forward to 

 a wider application as the precision of knowledge grows and as, also, 

 we become more familiar with the scientific facts which govern such 

 micro-organisms. Eighty per cent of the air is nitrogen. There is, 

 therefore, a large fund of nitrogen in the air from which to draw, and 

 if it can be used for the fertilization of plants, it can, consequently, 

 be used for animal growth, and life will be continued much longer than 

 we supposed 20 years ago. 



PERiMENTATION BACTERIOLOGY. 



This is a branch of bacteriology which has been Avorked thoroughly 

 for the past liO years. The work of Pasteur and Hansen is already seen 

 iii many of the fermentation industries, and it is generally conceded 

 by these industries that the experiments of these men may be considered 

 invaluable in the development of uniform fermentations, in the control 

 of oft"- fermentations, and in the selection of those species which give 

 the greatest yield and the best T)roduct. At present, there are many 

 laboratories which devote their entire attention to the physiology and 

 morphology of fermentations, and these laboratories are utilized in pre- 

 ]>aring men to enter into the service of these fermentation industries 

 lor the purpose of studying the best methods of procedure and also for 

 the purpose of improving the fermentations. It is safe to say, espec- 

 ially as it is founded upon actual statistics, that millions of dollars 

 have been saved annually to each of several countries through their 

 power to produce uniform results and to eliminate possible abnormal 

 fermentations from their manufacture. 



In many of these fermentation industries, so careful are they to hold 

 to the correct methods and correct species of micro-organisms, that 

 the manufacturing ])lant becomes a veritable bacteriological laboratory. 

 In this country, many farmers have great concern over the production 

 of vinegar. Although we have been brought up largely in the belief 

 that vinegar will always come from cider, any one familiar with the 

 industry at large, has observed the- fact that thousands of dollars of 

 loss occur yearly through ignorance of the processes involved. If it 

 were possible to acquaint farmers with the nature of the fermentation 



