Makoh 18, 1921] 



SCIENCE 



247 



drop to the mean level in this regard. There 

 can be little doubt but that the pendulum is 

 swinging from the extreme degree in special- 

 ized medicine so that in a few years the nor- 

 mal balance between the specialist and the 

 general practitioner will be established. 



Along with the growth of specialized medi- 

 cine has come the laboratory, which at the 

 present time is the brain of practical scien- 

 tific medicine. It is to the laboratory that we 

 are chiefly indebted for all of the great dis- 

 coveries in medicine and the allied sciences. 

 The beginning of this era of laboratory work 

 was the establishing of Von Ziemssen's lab- 

 oratory in Munich in 1885. 



Among the great discoveries which we owe 

 to the laboratory are Pasteur's work on patho- 

 genic microbes, in which he brought out the 

 theory of protective inoculation against cer- 

 tain infectious diseases. Later on he gave to 

 the medical world the results of his studies on 

 rabies and anthrax, which have been of im- 

 measurable service to mankind throughout the 

 civilized world. 



About the same time Koch introduced a 

 new method for the isolation and pure culture 

 of bacteria which is essentially the same as is 

 now in use. In 1874 Ehrlich iiaproved the 

 method of staining smears which had been 

 worked out by Weigert three or foiir years 

 previously. This opened the door to the study 

 of a great number of microorganisms and has 

 proven one of the most important diagnostic 

 criteria in the practise of medicine. As a re- 

 sult of Weigert's and Ehrlich's laboratory 

 technique the spirillum of relapsing fever was 

 discovered in 1873 by Obermeier and the 

 parasitic amoeba in dysenteric stools by 

 Loesch in 1875. Koch was able to grow 

 anthrax bacilli for the first time in artificial 

 media in 1875. In 1879 l^Teisser annoimced 

 the discovery of the gonococcus. In 1880 

 Pasteur presented his monograph on the study 

 of the streptococcus and the staphylococcus 

 which had been isolated for the first time by 

 him two years previously. About the same 

 time Eberth described the typhoid bacillus as 

 the cause of the continued fever known as 

 typhoid. Laveran discovered and described 



the Plasmodium of malarial fever, November 

 6, 1880. 



Perhaps the most important of these dis- 

 coveries and the one which attracted instantly 

 the most wide-spread attention among the 

 laity as well as the medical profession was 

 that of the tubercle bacillus by Koch in 1882. 

 Tuberculosis had been known and observed 

 for centuries, but the microorganism which 

 produced it had eluded all of the keenest ob- 

 servers up to that time. Another almost 

 equally important discovery made by Klebs in 

 1883 was the diphtheria bacillus; its causal 

 relation to diphtheria was demonstrated by 

 Loeffler in the same year. Along about this 

 time came the discovery of the tetanus bacil- 

 lus, the colon bacillus, the meningococcus, the 

 bacillus of Malta fever and a number of 

 others. Still another contribution along this 

 line was that of Smith and Kilbourne, who 

 discovered that Texas fever was transmitted 

 by the cattle tick. However, some years 

 antedating the announcement of Smith and 

 Kilbourne, Dr. A. F. A. King, of this city, 

 read a paper before this society in which he 

 expressed the belief that malaria was trans- 

 mitted by the mosquito. This may, and prob- 

 ably did, give a hint as to the transmission of 

 certain infectious diseases, which led to valu- 

 able discoveries, chief of which was that of 

 Reed and Carroll of this city, who demon- 

 strated that yellow fever was transmitted by a 

 certain species of mosquito; thus corroborat- 

 ing Dr. King's theory. As a result of this 

 discovery Cuba was made safe to the traveler 

 and the completion of the Panama Canal was 



Another notable contribution to practical 

 bacteriology was the discovery in 1896 by 

 Widal of the agglutination test for typhoid 

 fever, upon which the present-day difFerential 

 diagnosis between typhoid and other con- 

 tinued fevers rests. 



With the mention of one additional im- 

 portant discovery I will pass on to develop- 

 ments in other fields. Perhaps none of these 

 mentioned heretofore have arrived at a more 

 prominent place in the history of valuable 

 discoveries than Wassermann's serodiagnosis 



