DIAGNOSIS BY AGGLUTINATION TEST. 385 



over them drop by drop. For small sections three or 

 four drops are sufficient. Under no circumstances 

 should the alcohol be allowed to act for more than 

 one-quarter of a minute. Clear in xylol and mount 

 in xylol balsam. 



By method b the tissues are better preserved than by 

 method a, by which they are dried. 



In properly stained tissues the bacteria will be found 

 most numerous in the centre of the nodules, becoming 

 fewer as we approach the periphery. They usually lie 

 between the cells, but at times may be seen almost 

 filling some of the epithelial cells, of which the nodule 

 contains more or less. They are always present in 

 these nodules in the tissues ; they are rarely present 

 in the blood, and, if so, in only small numbers. 



DIAGNOSIS OF THE DISEASE BY THE AGGLUTINA- 

 TION TEST. The quickest and surest method of recog- 

 nizing the disease is by the specific agglutinating effect 

 of the serum of the diseased animal upon the organism 

 of the disease. Many different plans have been recom- 

 mended. That of Moore, of Cornell University, is one 

 of the most trustworthy. He recommends a test emul- 

 sion made by suspending a glycerin agar culture of 

 glanders bacilli in physiological salt solution. This is 

 then exposed to 60 C. for two hours, whereby the bac- 

 teria are killed, and is finally preserved by the addition of 

 0.5 per cent, carbolic acid. To this suspension the serum 

 of the suspected animal is added in varying proportions 

 until a distinct clumping and sedimentation of the bac- 

 teria is observed. Whenever done in a small test tube of 

 about 0.5 c.m. in diameter this reaction manifests itself 

 as a gradual clarification of the milky fluid and the accu- 

 mulation of a mass on the bottom of the tube. Normal 



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