362 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



and has jiroved very satisfactory. Samples of sera have been for- 

 warded for dia2:nosis to the bureau Laboratory from all over the 

 United States, and they have become so numerous that it has become 

 necessary to place restrictions on the work. It is regrettable that 

 we do not always receive the post-mortem findings in cases which 

 are diagnosed as positive by this method, but judging from the in- 

 stances in which the autopsy findings have been reported, the com- 

 bined tests appear to be accurate in over 98 per cent of the cases. 

 In all more than 3.200 animals have been tested by this method, and 

 the bureau is encouraging the State as well as the municipal au- 

 thorities to adopt this method of diagnosis, which at the present time 

 is undoubtedly the most accurate laboratory test at our command 

 for the determination of the disease. 



Such tests, of course, will always continue to be strictly confined to 

 well-equipped laboratories, and therefore it is desirable to establish a 

 method of diagnosis for glanders which could be undertaken by the 

 practicing veterinarian and which at the same time would be more 

 accurate than the subcutaneous mallein test. The favorable reports 

 of results obtained from the ophthalmic reaction in the diagnosis of 

 glanders in Europe suggested the application of this test in order to 

 determine its accuracy. This method is followed extensively in 

 Austria and constitutes the official test of that country. The Euro- 

 pean investigators suggested for use in these tests either the " mallein 

 brut," which is a concentrated form of the ordinary mallein, or a 5 

 per cent watery suspension of the alcoholic precipitate of this product. 

 In the w^ork of the bureau the mallein has been prepared by concen- 

 trating the mallein used for the subcutaneous tests to one-tenth of its 

 original volume without the addition of glj^cerin or carbolic acid. 

 The application of the mallein into the e3^e is made with the aid of a 

 camel's-hair brush. After sterilizing the brush, it is dipped into the 

 mallein, the eye being opened in the manner practiced in the examina- 

 tion of the conjunctiva, and the brush is drawn once forward and 

 backward over the eye. The application is made into one eye only, 

 while the other is used as a check. The test should not be undertaken 

 in the presence of any inflammatory conditions in the eye. Twenty 

 hours subsequent to the application of the mallein to the eye the 

 reaction is read. The presence of a purulent discharge together with 

 conjunctivitis indicates the presence of the disease. 



In most instances the reaction is very prominent and may be recog- 

 nized at a glance. 



The results obtained by this test have proved very encouraging 

 and highly satisfactory. In all positive cases the reaction was very 

 pronounced and the presence of the disease confirmed by autopsies, 

 w^hile negative cases controlled by the agglutination-fixation test 

 showed no reaction whatsoever. The test in our hands has been 

 found to be superior to the subcutaneous mallein test, and has, 

 besides, the advantage that after the application of the mallein into 

 the eye it is only necessary to examine the animals about 20 hours 

 subsequent to the administration. 



TETANUS. 



AVith the discovery of the cause of tetanus by Nicolaier in 1884 and 

 the successful experiments on immunization by Kitasato and Von 

 Behrmg in 1890, a wonderful advance was made in our knowledge of 



