44 STATE BOARD OF AGRICULTURE. 



notable and practical result of this has become familiar to most peo- 

 ple in the treatment of diphtheria. Its value is best appreciated by the 

 })hysician who has made use of diphtheria anti-toxin serum. How far 

 the work may eventualh' be carried, and how many diseases controlled, 

 no one is able to predict. There is much of the present, as much as in 

 any great science, but its future glows with probabilities and the good 

 it may do for mankind. 



No greater value could be adduced for this science than that to be de- 

 rived from its contributions to the manipulation of water supplies and 

 sewage disposals. Here it has been the means of reducing the mortal- 

 ity of cities from fevers and choleras; in other words, from a high to 

 a low rate of mortality, because it has been the one factor wanting 

 for the devising of controlling agents. A knowledge of micro-organ- 

 isms has made it possible to create and manage filter beds which are 

 under constant bacteriologic observation. Sewage is also beginning to 

 lose its peculiar significant meaning as related to diseases of various 

 kinds. The future promises unpolluted water supplies and complete 

 sewage destruction with harmless fertilizer production, not only to cities, 

 villages and populated centers, but to rural homes as well. 



DAIRY BACTERIOLOGY. 



The relation which bacteriology holds to medicine is, in many re- 

 spects, the same as it holds to dairying. It is possible to designate the 

 fermentations occurring in milk as diseases to which milk is heir. The 

 transmission of disease by means of milk might more strictly belong to 

 hygienic bacteriology, yet it also has an important place in this di- 

 vision of the science; and no little importance can be attached to it, 

 for, to a great extent, the welfare of the race is dependent upon a pure 

 milk supply — a milk free from the micro-organisms which are capable 

 of initiating disease processes and producing toxic action. It is de- 

 sirable, therefore, that an understanding should be had of the avenues 

 by which germs reach the milk and are conveyed by it, as such knowl- 

 edge will contribute much to the restriction of milk-borne diseases. 



Again, although there are many micro-organisms capable of causing 

 changes in milk in the udder and outside, they cannot be regarded as 

 dangerous from a health standpoint, but, on the other hand, they cause 

 mischief through their ability to set up various obnoxious fermenta- 

 tions. Every germ seems to have a specific action upon milk; conse- 

 quently, possibilities of changes in milk are indefinite. In these fer- 

 mentaions are found the various troubles arising with milk consumers 

 and those who would manufacture dairy products. It is true that with- 

 out these fermentations, and also without the possibility of transmission 

 of disease through milk, the bacteriologist would find little opportunity 

 in milk for investigation and work. But, with the conditions as we find 

 them, and also with some commercial fermented products of milk, the 

 field of action becomes exceedingly broad ; in fact, so broad that many 

 bacteriologists do not attempt to pass its boundaries. To ward off or 

 control the fermentations or off-conditions of milk; to check the trans- 

 mission of diseases through milk ; to encourage and foster those changes 

 which will eventually give rise to satisfactory products; and to study the 

 technique of germ manipulation are, in general, the broad divisions of 



