788 Syphilis 



therefore, their probable cause. The observations of Schau- 

 dinn and Hoffmann, quickly confirmed by Metschnikoff,* 

 have now been universally accepted. 



Morphology. The organism is a slender, flexible, closely 

 coiled spiral, usually showing from eight to ten uniform un- 

 dulations, but occasionally being so short as to show only 

 two or three, or so long as to show as many as twenty. 



It is very slender, measuring from 0.33 to 0.5 [A in breadth 

 to 3.5 to 15.5 11 in length (Levaditi and Mclntosh). 



It forms no spores. Multiplication seems to take place by 

 longitudinal division. 



It is motile, and when observed alive with a dark field 

 illuminator, can be seen to rotate slowly about its longitu- 

 dinal axis at the same time that it slowly sways from side 

 to side with a serpentine movement. The organisms are 

 provided with flagella at one end, sometimes one at each 

 end. 



Noguchif observed two types of treponema, one slender, 

 one stouter. When carried through culture and used to in- 

 oculate rabbits their differences were found to be fairly con- 

 stant. The lesions produced in rabbit's testicles varied with 

 the variety of organism inoculated, one causing a diffuse, the 

 other a nodular, orchitis. He conjectures that the distinction 

 may be of value in explaining certain obscure points in human 

 syphilis. 



Staining. The original discovery of the organism was 

 achieved through the employment of Giemsa's stain a 

 modification of the Romanowsky method. But by this 

 method the organisms appeared very pale and not very 

 numerous. GoldhornJ improved the method as follows: 



In 200 c.c. of water, 2 grams of lithium carbonate are dissolved and 

 2 grams of Merck's medicinal, Griibler's BX, or Koch's rectified methy- 

 lene-blue added. This mixture is heated moderately in a rice boiler 

 until a rich polychrome has formed. To determine this a sample is 

 examined in a test-tube every few minutes by holding it against an 

 artificial light. As soon as a distinctly red color is obtained, the desired 

 degree of heating has been reached. After cooling it is filtered through 

 cotton in a funnel. To one-half of this polychrome solution 5 per cent, 

 of acetic acid is gradually added until a strip of litmus-paper shows 

 above the line of demarcation a distinct acid reaction, when the re- 

 maining half of the solution is added, so as to carry the reaction back 

 to a low degree of alkalinity. A weak eosin solutioa is now prepared, 



* "Bull. Acad. de med. de Paris," May 16, 1905. 



t "Journal of Experimental Medicine," 1912, xv, No. 2, p. 201. 



{Ibid., 1906, vin, p. 451. 



