EXPERIMENT STATION REPORTS. 155 



say tliaL the iicud-ality was obtained by u(]<liiig- very small quantities 

 of a linndredtli normal alkali or acid. 



(7) In rei'-ard to the chemical analysis you will not be surprised 

 to hear that all nutritive substances could be found in our soil solution 

 to u certain dejiree. An aslonishinjj;- fact, however, is the relatively 

 larg-e quantity of nitrates in some samples. With reference to the value 

 of the chemical analysis of the soil solution, T refer to that Avliich I 

 have already said. 



Our work can by no means be looked ujjon as complete, but I dare 

 say that the results are promising-, nnd that I feel happy to be able to 

 present to the reader the preliminary results which have been obtained 

 by the application of the methods of Mr. Itano and myself. 



LITERATURE. 



1. F. Hessclink van Suchtelen, Centr. bl. f. Bakt. TT Abt. Bd. 28, S 45. 



2. F. Stockhausen, Okologie Anhaiifungen nach Beyerinck. 



3. A. Mitscherlich, Bodenkunde fiir Land und Forstwirte, 1905, p. 



49-73. 



4. Bull. No. 30, Bureau of Soil, U. S. Dep't. of AgTiculture. 



Mr. C W. Brown has continued his investigations on the keeping 

 qualities of butter and has nearly ready for publication the data relative 

 to another phase of this problem. It is expected that this immediate 

 problem will be completed during the ensuing year during which time 

 it is hoped that Mr. Brown will devote considerable time to problems 

 concerning the nodule-forming bacteria. Plans are being made to furnish 

 assistance for this work. 



Dr. E. T. Hallman has assumed the duties that I was formerly con- 

 cerned with. He has assisted the Live Stock Sanitary Commission in 

 a manner that has gratified all parties concerned. He has also devoted 

 considerable time to a study of some of the problems connected with 

 hog cholera; but his most important work has had to do with "infectious 

 abortion in cattle. Immunization experiments and the possibility of 

 using the complement fixation and agglutination tests have formed the 

 basis of the work. We feel hopeful that these researches will eventually 

 be fruitful. In the meantime, we are adopting a policj^ of caution 

 and watchfulness. Dr. Hallman submits the following notes which 

 should be recorded here: 



My work with infectious abortion of cattle is a continuation of the 

 work begun by Dr. Giltner. We are pursuing two lines of investigation : 

 first, a study of the means at our command for the diagnosis of the dis- 

 ease, and second, the search for some practical, effective method of con- 

 trolling the disease. 



The first line of investigation is an exceedingly important one in our 

 estimation. If abortion occurs in a herd the first question to arise is 

 ''Is it infectious, and if so. to what extent is the infection present?" 



Considerable work has been done with the agglutination and comple- 

 ment fixation tests in this disease and many investigators consider them, 

 especially the latter, a very accurate method of determining the presence 

 of infectious abortion in a herd. We believe that with these tests 

 we can determine with a fair degree of accuracy whether infectious 

 abortion is or is not present, but can we determine the extent of in- 

 fection? What is the significance of a positive reaction? Does it mean 



