CLASSIFICATION OF PNEUMOCOCCI 123 



specific substance, or precipitinogen, from the pneumococcal cells 

 during growth in the peritoneum of the test animal. 



CULTURE AGGLUTINATION 



In 1918, two rapid methods were announced. The urgency of 

 war-time needs, the lack of laboratory facilities in the hastily im- 

 provised army camps, and the shortage of mice, all called for a 

 simplification and speeding up of the methods for pneumococcal 

 type determination. Taking advantage of the more rapid growth 

 of pneumococci in sugar broth, Avery 34 planted washed sputum in 

 bouillon containing one per cent glucose and after five hours' incu- 

 bation, that is, in the period of active growth of pneumococci and 

 before accompanying bacteria had multiplied to any conflicting 

 extent, the broth was used as an agglutinating antigen with the 

 three type serums. This procedure gave a high percentage of suc- 

 cessful results, besides being simple, inexpensive, and speedy of 

 execution. Oliver 1026 later made the suggestion that the Andrade 

 indicator be added and that inulin be substituted for dextrose in 

 the Avery medium, because these modifications yielded better re- 

 sults and were successful in cases when dextrose broth failed. 



An exception to the general experience with the Avery method 

 was that reported by Beckler, Marden, and Gillette, 97 who had a 

 number of failures with this test as compared with mouse inocula- 

 tion. Since they had no control over the collection of the speci- 

 mens, the work being done in a state diagnostic laboratory, the 

 sputum was often mixed with saliva, which the authors thought 

 might account for their unsatisfactory experience. Those readers 

 desiring to learn of the operation of the Avery rapid cultural 

 method in the field should consult Vaughan 1448 who gave (1918) a 

 description of laboratory requirements and satisfactory results in 

 army base hospitals. 



URINE PRECIPITATION TEST 



Another diagnostic, or more exactly prognostic, aid of the same 



