752 



SCIENCE 



[N. S. Vol. XXXIX. No. 1012 



earliest of tlie eighties, the laboratories got 

 intensely busy in the search for new species of 

 germs; and as fast as forms were discovered 

 which incite disease, the knowledge of how 

 they look and what they do and how they may 

 be restrained or destroyed was turned to the 

 service of man and beast. 



But the researches were not long content to 

 spy upon the perfoi-mances of the germs. 

 What the living threatened body does to pro- 

 tect itself against them when once they gain a 

 foothold became a subject of wide and fruitful 

 inquiry. So the facts and doctrines and 

 guesses relating to immunity and to infection, 

 either natural or acquired, came to the front. 



Pasteur had got some wonderful results in 

 the experimental conference of immunity to 

 infection, by gradually adapting animals to 

 disease-inciting germs, which were living, but 

 whose virulence and potency had been artifi- 

 cially reduced. It was then supposed that only 

 the subtle action of the living germ could 

 conjure forth the remarkable protective power 

 apparently created in artificial immunity. 

 Many others were at work on these and kin- 

 dred lines; Dr. Smith among them. But he 

 noticed, and was the iirst with Salmon to an- 

 nounce in 1886, that animals could be immu- 

 nized not only by living germs but by cultures 

 of these which had been sterilized and every 

 vestige of life destroyed. 



This announcement did not seem to start 

 even a ripple in the bacteriologic pool. But 

 the thing was in the air. There were many 

 busy workers, and sooner or later such a record 

 helps more than is commonly realized another 

 explorer who is heartened to find his pathway 

 not quite untrod. 



Very soon it had been shown that immunity 

 to diphtheria may be secured in animals not 

 only by the living germs, but by the sterile 

 products of their life processes. Thus with 

 the names of Loeffler, Behring, Eoux, Yersin 

 and many others, opens the story of diphtheria 

 antitoxin and its marvellous benefactions to 

 mankind. 



And so again, every horse which is turned 

 to the uses of suffering mortals and gets his 

 dosage of sterile diphtheria culture broth for 



the manufacture of antitoxin, is but another 

 exemplar of the principle which first crystal- 

 lized in the light of the response which Dr. 

 Smith's pigeons made to the sterile hog- 

 cholera bacillus cultures, at that early day, 

 close to the dawn of the bacteriologic era in 

 biolog,y and medicine. 



Dr. Smith has devoted a great deal of time 

 and energy to the study of diphtheria and 

 other antitoxins, both as professor of com- 

 parative pathology at Harvard and as the 

 director of the antitoxine and vaccine labo- 

 ratories of the Massachusetts State Board of 

 Health. As is the case with most acute ob- 

 servers in these uncharted fields of bacteriology 

 and immunity, he has encountered many 

 striking phenomena which the lore of the time 

 had not satisfactorily classified or accounted 

 for. One of these carries a little story. 



When Ehrlich was in this country in 1904, 

 Professor Smith called his attention to the 

 singular fact that guinea-pigs which he was 

 using to test diphtheria antitoxin, sickened 

 and died upon being injected with normal 

 horse serum several weeks after they had been 

 injected with diphtheria antitoxin. Guinea- 

 pigs usually do not mind normal horse serum 

 at all. Such an extraordinary sensitiveness to 

 normal serum, following earlier injections 

 seemed something new and unaccountable, and 

 when Ehrlich got back to Frankfort he gave 

 the problem to Dr. Otto, who labored with it 

 and presently wrote a paper on what — with an 

 attitude of undismay toward stately adjectives 

 that is characteristically German — he called 

 the " Theobald Smithsche Phenomenon." 

 Nowadays the yearly lists of the achievements 

 of research in infection and immunity fairly 

 swarm with studies on " anaphylaxis," a phase 

 of immunity of which Professor Smith's 

 guinea-pigs afforded one of the first recorded 



In the early days of bacteriology Dr. Smith 

 called attention to the value of a bent glass 

 tube, closed at one end, such as was already in 

 use by the chemists, for the purpose of culti- 

 vating many types of bacteria and studying 

 their biological characters. This is of especial 

 value in the culture and study of the class of 



