452 APPLICATION OF METHODS OF BACTERIOLOGY 



Diagnosis of the Disease by the Agglutination Test. — ^The 

 quickest and surest method of recognizing 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 recommended. That of Moore, of Cornell 

 University, is one of the most trustworthy. He recommends 

 a test emulsion 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 bacteria 

 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 bacteria is 

 observed. Whenever done in a small test-tube of about 

 0.5 cm. diameter this reaction manifests itself as a gradual 

 clarification of the milky fluid and the accumulation of a mass 

 on the bottom of the tube. Normal horse serum in a dilution 

 of 1 to 300 to 1 to 200 causes the agglutination, while that 

 from glanders animals does the same in from 1 to 3200 to 

 1 to 500 dilution. The "complement fixation" reaction 

 may also be applied both for the recognition of the condi- 

 tion — i. e., for detecting the specific antibodies in the tissues 

 or fluids, as well as for the identification of the specific 

 exciter of the condition — i. e., the antigen. (See that 

 reaction.) 



Mallein.— The sterile filtered products of growth of the 

 glanders bacillus in fluid media represent what is known as 

 mallein — a solution of compounds that bear to glanders a 

 relation analogous to that which tuberculin bears to tuber- 

 culosis. It is used with considerable success as a diagnostic 

 aid in detecting the existence or absence of deep-seated 

 manifestations of the disease, the glanderous animal reacting 



