PRACTICAL APPLICATIONS 293 



described by Kolmer 1 ; Nakano, 2 Kissmeyer, 3 and Zinsser and Hopkins 4 

 have also described the agglutination of culture pallidum by immune 

 serum. Kolmer, Broad well and Matsunami 5 found that equal parts of 

 normal human serum and pallidum culture furnished by Zinsser, may 

 result in partial agglutination, whereas with sera of syphilitics in the 

 later stages, agglutination in dilutions of 1 : 5 and higher occurred 

 with about 84 per cent, of sera, but that further studies are neces- 

 sary to establish the practical value of agglutination in the diagnosis 

 of syphilis. 



In pertussis agglutination tests have been found of some value in 

 clinical diagnosis by Wollstein, 6 Frankel, 7 Seiffert, 8 and Arnheim; Borclet 9 

 finds it of value only when the microorganism is freshly isolated from 

 human sputum and grown on rich blood medium . According to Po vitsky 10 

 and Worth 11 a dilution of serum not less than 1 : 200 is necessary for 

 a practical positive diagnosis of pertussis, as normal human serum may 

 agglutinate in dilutions up to 1 : 100. 



In veterinary practice agglutination reactions are of value in the 

 diagnosis of glanders, infected horses reacting in some instances to dilu- 

 tions as high as 1:2000. For diagnostic purposes the agglutination 

 test in glanders must be in dilutions higher than 1:800. A positive 

 reaction in dilutions of 1:1000 is regarded as suggestive, and is con- 

 trolled by a complement-fixation test; agglutination in dilutions of 

 1 : 1500 practically always indicates an infection. The complement-fixa- 

 tion test, however, is a better diagnostic reaction. 



2. Agglutination reactions are also of value as an aid to the identi- 

 fication of a microorganism that has been cultivated from a patient. 

 For this purpose we must have on hand various standard immune 

 serums. For example, if a bacillus resembling the typhoid bacillus is 

 isolated from the feces of a patient, the diagnosis may be aided by a 

 positive agglutination reaction with typhoid immune serum. 



1 Jour. Exper. Med., 1913, xviii, 18. 



2 Archiv. Dermat. u. Syph., 1913, cxvi, 265. 



3 Deutsch. Med. Wchnschr., 1915, xli, 306. 



4 Jour. Exper. Med., 1915, xxi, 576. 



5 Jour. Exper. Med., 1916, xxiv, 333. 



6 Jour. Exper. Med., 1909, xi, 41. 



7 Munch. Med. Wchnschr., 1908, Iv, 1683. 

 s Munch. Med. Wchnschr., 1909, 1561. 



a Berl. klin. Wchnschr., 1908, xlv, 1453. 



10 Centralb. f. Bakteriol., orig., 1912, Ixvi, 276. 



11 Archiv. Int. Med., 1916, xvii, 279. 



