304 THE NEW WORLD OF SCIENCE 



nor to one another in their own group. In fact, they resemble 

 in this the organisms found in the normal, healthy human 

 mouth. From a study of these clearly defined types it has 

 been possible to prepare a serum which is curative when given 

 sufficiently early in the disease, for the lobar pneumonia caused 

 by organisms of type one. Similar curative sera have not yet 

 been prepared for the other types. In a study of 454 cases 

 of pneumonia at the Rockefeller Hospital, it was learned that 

 about one-third of all cases are caused by type one, a second 

 third by type two, about 13 per cent, of type three and the 

 remainder, 20 per cent., by type four organisms. We have 

 then, a specific treatment for about one-third of all cases of 

 lobar pneumonia. The mortality of this type of the disease is 

 normally about twenty-five per cent., but under treatment with 

 serum in suitable surroundings the mortality may be reduced 

 to ten per cent. This treatment was rapidly gaining ground, 

 but, like other new things in medicine, had not yet become 

 generally accepted through the country, and very few hospitals 

 or physicians were prepared to make the bacteriological diag- 

 nosis or to apply the indicated treatment. To provide for this 

 condition, classes of otherwise well-trained bacteriologists and 

 clinicians were organized in our principal hospitals and labora- 

 tories, and systematic courses of instruction were given. 

 Several hundreds of the younger medical officers passed through 

 the Army Auxiliary Laboratory No. One at the Rockefeller 

 Institute and the Yale Army Laboratory School at New Haven. 

 When these men were distributed to our large base hospitals 

 they in turn organized schools for special instruction of the 

 staffs in the diagnosis and treatment of the diseases of the 

 lungs, including tuberculosis, of empyema, and of cerebro- 

 spinal meningitis, and of the other commoner epidemic diseases. 

 Nothing in the medical history was more inspiring than the 

 spirit and energy with which our men undertook the study and 

 systematic investigation of the important problems which con- 

 fronted them. The greatest of all the new fields was in the 

 respiratory diseases which were unusually common, quite severe 



