366 



it is found that the beets j^iowu with irrigation, by which the moisture 

 in the soil is subject to the control of the farmer, are especially rich in 

 suji^ar. Already sugar factories have been established in !N'ebraska, 

 California, and Utah, and it is estimated that about 13,000 tons of beet 

 sugar were made in this country during the past year. 



In a similar way tlie experiiiu'nts in the use of alcohol in the making 

 of sorghiun sugar, conducted bj' this Deijaitment, have been highly 

 successful. It is believed that this process will double the amount of 

 crystallized sugar to be obtained from a given quantity of cane at a 

 trifling increase in cost. Experiments on a fiictory scale have already 

 shown such results. This process gives an unusually pure product, the 

 sugar being fit for many purposes "without refining. 



The past year's work in testing the devices contrived by the stations 

 for rapidly determining the amount of fat in milk, has made it rea- 

 sonably sure that dairymen and creameries have at their disposal a 

 practical method which will enable them to fix the value of each cow's 

 milk according to its quality. The farmer no longer has any excuse for 

 keeping unx>rofitable stock and the creameries have no valid reason fur 

 refusing to pay for milk on the basis of its quality. 



Among more strirtly scientific investigations in agricultural lines 

 none have attracted greater attention duiiug 1801 than those in which 

 the lunctions of bacteria have been the subject of inquiry. Our 

 knowledge of the ])athogcnic bacteria has been extended. This Depart- 

 ment has published an inqiortant report on the <-auses and prevention 

 of swine plague, in whicli it is definitely shown that swine plague and 

 hog cholera are distuict diseases, each having an easily recognizable 

 specific germ. Interesting researches have also been made in the 

 application of Koeli's lymph to the diagnosis of tuberculosis in domestic 

 animals. But the observations on bacteria which are useful to agricul- 

 tiue have been far more striking in their results than any reported on 

 injurious bacteria. 



The question as to the cause (»f the nitrification of ammonium saltsin 

 soils has recently found a definite answer in the investigations of Wino- 

 gradsky at Zuri<'h. The nitrifying organisms so often searched for seem 

 to have been found, successtrilly isolated and cultivated, and their 

 characters, nitrifying action, and methods of culture carefully studied. 



The most recent investigations of Lawes and Gilbert. Hellriegel, 

 IS^obbe, and others not only confirm the results of earlier inquiries which 

 have shown that bacteria are intimately connected with the acquisi- 

 tion of atmospheric nitrogen by leguminous plants through their root 

 tubercles but also indicate that particuhir species of bacteria perform 

 this service for the several kinds of plants. Some experiments even 

 indi( ate that bacteria may be turned to practical account in the produc- 

 tion of leguminous crops. For example, it has been found on a small 

 scah^ that the s]»rinkling of soil containing lupine bacteria over other 

 soil in which lupines had been planted, promoted the growth of these 

 plants. 



