VIII, B. 1 Ashhurn, Vedder, Gentry: Variola and Vaccinia 27 



POSTSCRIPT 



Only since writing the above article have we been able to obtain 

 Ricketts and Bayles' Diagnosis of Smallpox. These authors, 

 while not entertaining our views as to the dual and divisible 

 nature of smallpox virus, and holding strongly that vaccinia 

 protects against the whole of smallpox, nevertheless do con- 

 sider and speak of smallpox as a "dual disease," and say, "The 

 fever proper of smallpox is that of the septicaemia, and the local 

 rash and the secondary fever bear the same relation to it as 

 the pneumonia to measles, or the adenitis to scarlet fever." 

 Inasmuch as the pneumonia of measles and the adenitis of 

 scarlet fever are probably always due to invasion of bacteria 

 distinct from the viruses of the specific diseases, we regard 

 the analogy as fairly good. It would be better could the 

 pneumonia of measles or the adenitis of scarlet fever be shown 

 to be due always to one specific virus (as is the pock of variola) , 

 and could that virus, by cultivation or by growth in animals, 

 be obtained in a relatively pure and harmless condition and 

 used to immunize healthy infants against the entire disease, 

 or the more serious part of the disease, measles, or scarlet fever. 



Using Ricketts and Bayles' nomenclature in explaining our 

 view, we may say that smallpox is due to virus AB. Of these 

 (or the parts of this), A is mainly responsible for the "toxic 

 fever" and "toxic rashes," although possibly the combination 

 AB is necessary before A can manifest itself; B is responsible 

 for the "focal eruption" and for vaccinia. A's action is first 

 manifested, B'& follows, and it may be followed in turn by a 

 third cause of injury, for instance, a streptococcus or staphy- 

 lococcus infection. Complete immunity to B should constitute 

 at least partial and possibly complete immunity to AB, although, 

 should A be capable of acting alone, immunity to B would not 

 affect it. 



REFERENCES 



(1) COPEMAN. Journ. Path. & Bad. (1894), 7, 407. 



(2) Journ. Trap. Med. & Hyg. (1912), 15, 212. 



(3) Immermann. Nothnagel's Practice. Amer. ed. (1906). 



(4) Sternberg. Text Book of Bacteriology (1901). 



(5) Kelsch et al. Bull. Acad. vied. (1910), 44, 92. 



(6) Meirelles. Bull. Soc. path, exotique (1910). 



(7) StJPFLE. Arch. f. Hyg. (1908), 48, 237. 



(8) WOLBACH. Journ. Med. Research (1912), 27, 1. 



(9) Prowazek and Baurepaire. Miinch. Med. Wochenschr. (1908), 55, 



11. 



