94 KEPORT OF ^'ATIONAL MUSEUM, 1922. 



nient of rabies, the serobacterin treatment of typhoid fever and 

 whooping cough, and the principles of diagnostic skin tests used to 

 determine the cause of certain diseases and conditions of health. 

 They are a continuation of the series referred to in last year's 

 report, which is arranged to illustrate what vaccine (or bacterin), 

 serum, and serobacterin therapy are. The fundamental principle of 

 these forms of therapeutics is immunity, and the medicaments used 

 to produce this active or passive immunity are, in vaccine or bacterin 

 therapy, the infectious agents themselves; in serum therapy, the 

 blood serum of an animal that has been immunized against such 

 an infectious agent ; and in serobacterin therapy, the infectious agent 

 after it has been sensitized by the serum of an animal immunized 

 against that agent. 



While the mortalitj^ is slight from hydrophobia and man can pro- 

 tect himself from it by police measures, the mere mention of the 

 name evokes legendary visions of raging victims, bound and howl- 

 ing, inspiring terror in all those in their vicinity. Up to the time 

 of Pasteur every person and every animal that contracted the 

 disease died from it. Pasteur, the famous French bacteriologist 

 and scientist, basing his work on the discovery of Jenner that 

 vaccination with cowpox prevents smallpox and taking advantage 

 of the long incubation period of the disease, developed the present 

 system of immunization against rabies. Realizing that the full- 

 strength virus could not be administered at once without trans- 

 mitting the disease, Pasteur weakened or attenuated the action 

 of the virus, found in the spinal cord of an animal Avhich had died 

 of hydrophobia, by allowing a portion of the cord to become old 

 in contact with air. He proved that after 14 days the virus is 

 harmless, and that a dog which receives a properly prepared treat- 

 ment from a rabic spinal cord 14 days old, then the following day 

 from one 13 days old, then from one 12 days old, and so on until 

 the fresh cord is used, does not contract rabies and is inmiune to it. 



The serobacterin treatment of whooping cough aims to assist 

 nature to develop an immunity so that the effects of BaolUits per- 

 tussis^ the essential causative factor of the disease, and its toxins 

 may be overcome. Whooping cough causes about 10,000 deaths 

 every year in the United States, of which more than half occur in 

 infants less than a year old. 



It is said that during the Spanish-American War and the Civil 

 War the incidence of typhoid fever was 91.22 and 70.69 per cent, 

 Avithout serobacterin treatment, and in the American Expeditionary 

 Forces less than 0.1 per cent, with serobacterin treatment. 



Two charts of the series have been arranged to show hoAv physi- 

 cians determine the protein or proteins which give rise to systematic 

 disturbances, such as hay fever, asthma, and food idiosyncrasies. 



