1010 



SCIENCE. 



[N. S. Vol. XVI. No. 417. 



failed, and the bacteria have forced an 

 entrance into the body, what can scientific 

 medicine do to cure? Two things are 

 possible— the destruction of the destructive 

 germs, and the neutralization of their poi- 

 sonous toxins. The commonly recognized 

 drugs here prove inefficient, for the simple 

 reason that the amount of the drug suffi- 

 cient to kill the bacteria is so great as to 

 endanger the life of the patient. The most 

 promising line of treatment has been sug- 

 gested by the results of a study of the 

 mutual relations of the bacteria and their 

 hosts. Here again there are many gaps 

 in our knowledge. It is not surprising 

 that the cells of the body resent the int fu- 

 sion of the barbaric horde of microorgan- 

 isms, with their poisonous offscourings. 

 The cells are roused to unwonted activity, 

 and pour forth into the blood specific sub- 

 stances, which, in many cases at least, 

 seem to be of two distinct kinds, the cy- 

 tolysins and the antitoxins. Of these, the 

 cytolysins are destructive to the invading 

 bacteria, while the antitoxins are capable 

 of neutralizing, though in a manner not 

 wholly clear, the toxic products of bacterial 

 growth. Cytolysins oppose the bacteria, 

 while antitoxins oppose the bacterial toxins, 

 and the outcome of the disease depends on 

 the relative efficiencies of the contending 

 forces. If the invaders prove too power- 

 ful for the body cells, the individual si;c- 

 cumbs; if the defenders prevail, he re- 

 covers. 



With the picture of this natural conflict 

 before the mind, medical science asked : 

 'Is it not possible to aid the invaded body 

 by providing it with weapons of the same 

 kind as its own, but in larger quantity?' 

 This question medical science has answered 

 emphatically and affirmatively in the case 

 of two serious diseases, diphtheria and te- 

 tanus, or lockjaw. By making a pure cul- 

 ture of their germs, and injecting their 

 toxins into the bodies of animals, it can 



obtain a blood serum heavily charged with 

 antitoxin. This when injected into the 

 diseased human body supplements the anti- 

 toxin there found, "and by so much the 

 patient is aided in his struggle. With 

 both these diseases the success of the serum 

 treatment has been pronounced. A recent 

 study of 200,000 cases in which the anti- 

 toxin of diphtheria was used shows the 

 fatality from that disease to be reduced 

 from 55 to 16 per cent. The problems 

 presented by other infectious diseases seem 

 to be more difficult. What seems to be 

 required in most cases is a serum contain- 

 ing in cjuantity rather the cytolytic than 

 the antitoxic substance, and as yet an effi- 

 cient serum of this nature has not been 

 found. Any day may yield such an one. 

 But the matter of the relation of cytolysins 

 and antitoxins, and their respective effi- 

 ciencies in specific diseases, needs much 

 elucidation. Serum therapy is in its in- 

 fancy, _but its methods appear so rational 

 that it seems destined to develop into a 

 most efficient branch of scientific medicine. 

 Second only in importance to the cure 

 is the prevention of a future attack of the 

 disease, or, in other words, the conferring 

 of immunity on the individual. The dis- 

 ease itself, when running its natural course 

 within an individual, confers a natural 

 immunity against a subsequent attack, and 

 with many diseases this may prove to be a 

 life-long protection. Typhoid fever and 

 smallpox, for example, rarely attack the 

 individual a second time. In its. present 

 state the serum treatment also accom- 

 plishes immunity in some, though slight, 

 degree, but greater and more lasting effi- 

 ciency is desired. Probably no problem in 

 bacteriology is being attacked more vigor- 

 ously and more widely at the present time 

 than this. A suggestive hypothesis by 

 Ehrlieh as to the chemical relations of the 

 invading cells and the cells of the body 

 has stimulated investigations in many 



