100 REPOET OF NATIONAL MUSEUM, 1921. 



Next in importance is the accession covering the contribution of 

 the H. K. Mulford Co., of Philadelphia, Pa., illustrating vaccine and 

 serum therapy. Few of the present generation are aware of the fact 

 that smallpox, the most terrible of all the ministers of death, killed 

 at least 60,000,000 people in the 18th century, and that in preceding 

 centuries, about 10 per cent of all deaths were attributable to this dis- 

 ease. Millions of the survivors weakened, crippled, sightless, all bore 

 hideous traces of the power of this scourge. It was left for a humble 

 village doctor, Edward Jenner, in 178^ to conquer this disease by a 

 bit of virus on the point of an ivory lancet. It was he who dem- 

 onstrated to the world that this disease in the cow is mild, while in 

 man it is virulent, and introduced cowpox virus into the system of 

 human subjects to render them immune from the malignant type. 

 With compulsory vaccination, Jenner's discovery has become so effec- 

 tive that many active physicians have never seen a case of smallpox. 

 The average person knows comparatively little about this wonderful 

 discovery and the manner in which one of the greatest scourges to 

 mankind was conquered. An exhibit has been arranged in a manner 

 which tells something of the history of the discovery; the terrible 

 effects of the disease ; the trifling inconvenience of vaccination ; and 

 the modern sanitary methods of procuring the virus, etc. 



Another valuable medical discovery was that of the antitoxic 

 property of the blood serum of animals immunized by the inocula- 

 tion of bacterial toxins. The principle of this discovery, which was 

 ma^e in 1890 by Behring and Kitasato, is that the blood serum of a 

 subject which has recovered from an attack of a communicable dis- 

 ease caused by bacteria when transferred to another subject will 

 render the latter immune. Since this discovery, antitoxins for the 

 prophylactic and curative treatment of diphtheria and lockjaw have 

 been included in the United States Pharmacopoeia. All serums are 

 obtained in practically the same manner, and so an educational ex- 

 liibit was arranged to give the public a better understanding of the 

 theory and principles of serum therapy. The subject of" diphtheria 

 was chosen to illustrate in detail, and there follows exhibits relating 

 to lockjaw, pneumonia, and cerebrospinal meningitis. By means of 

 charts, photographs, and specimens Museum visitors are shown how 

 the bacteria which cause these diseases are grown in Loeffler's blood 

 serum; the manner of injecting these organisms into horses; how the 

 immunized horses are bled ; steps in obtaining the blood serum ; tests 

 for purity with filled syringes ready for administration; and mor- 

 tality tables showing the decrease in fatalities from these diseases 

 since this discovery. 



That hay fever is the result of pollen irritation is now an accepted 

 fact, and the protein sensitization theory has received a great deal 



