The Reliability of Sputum Typing and Its Relation to Serum Therapy

The serum treatment of pneumonia was first attempted more than forty years ago by Klemperer in Berlin and Elser in New York but could not be successfully introduced until different types of pneumococci were recognized and patients suffering from pneumonias due to specific types were treated with homologous serums. RECOGNITION OF TYPE Possibly the most important recent advance in the serum treatment of pneumococcic pneumonia is the more rapid determination of the invading type. This has been accomplished by the introduction and popularization of the direct method of sputum typing based on an observation of Neufeld,¹published in 1902, that in the presence of homologous serum the capsule of the pneumococcus became swollen. This method was proposed by Armstrong²three years ago, although it had already been used intermittently by Etinger-Tulczynska³in Neufeld's laboratory for a number of years. She employed a dye to outline the capsule