ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 333 



0*25 to 0'5 per cent., and it also contains a little calcium phosphate. 

 The potato becomes stained throughout of a deep indigo colour. 

 After becoming nearly black the pigment fades, ultimately assuming a 

 dirty-brown hue. The blue pigment is soluble in water and dilute 

 alcohol. Dilute alcohol is used for extracting the pigment from the 

 medium ; the alcoholic extract is passed through a porcelain filter. The 

 pigment is purified by precipitation with alcohol and re-dissolving in 

 water, the procedure being repeated several times. 



Cultivation of Ducrey's Bacillus. — G. Marechal* obtained, on ascitic 

 serum, pure cultures of the bacillus found in soft chancres, Ducrey's 

 bacillus. The serum was used alone, and in conjunction with agar, 

 gelatin, ox and horse serum. The microbe had the typical figure of 8 ap- 

 pearance. When transferred to slightly acid urine it became five or six 

 times the usual length, and often presented appearances similar to the 

 streptobacillus of Unna. When pure cultures were injected into the 

 peritoneal sac of guinea-pigs, the animals died in 12 hours, while sub- 

 cutaneous inoculations reproduced the appearances of soft chancre. 



F. Besancon, V. Griffon, and L. Le Sourd f recommend " sang gelose " 

 for cultivating the bacillus of soft chancre, as typical colonies develope 

 in 24 hours, and attain their full growth in 48 hours. The medium is 

 rabbit's blood mixed with agar. J 



Cultivation of Microbes of Vaccinia and Variola. — Dr. S. M. 

 Copeman § used collodion capsules filled with beef-broth. These, having 

 been inoculated with a trace of glycerinated vaccine-lymph, were sealed 

 up and placed within the peritoneal sac of rabbits and dogs. In suc- 

 cessful cases (i.e. when the capsulos did not rupture) it was found that 

 an appreciable amount of serum albumen had dialysed through. On 

 making film preparations of such unruptured capsules and staining with 

 methylen-blue, numerous zoogloea masses were detected. These masses 

 consisted of bodies resembling spores, only the periphery of which took 

 the stain. These apparently represent the resting stage of the specific 

 microbe. The contents of these capsules produced a typical eruption of 

 vaccinia in the calf. Organisms similar in appearance were observed in 

 the epithelium of vesicles in vaccinia of the calf and in human small- 

 pox. 



Dr. M. Funck || has found in vaccinia and variola a protozoon, 

 Sporidium vaccinale, which may be conveniently examined in emulsions 

 of glycerinated vaccine with bouillon or physiological salt solution. The 

 organism occurs as — (1) round bodies 2-10 /x in diameter, of a brilliant 

 green colour, and exhibiting slow movements ; (2) brilliantly green 

 spherules 1-3 /x in diameter, packed within epidermal cells ; (3) rasp- 

 berry like bodies, with a diameter of 25 /x or more. These cysts are full 

 of spores, and are termed sporoblasts. These sporoblasts were isolated by 

 the following procedure : — Some pure vaccine was spread on a disc of 

 ordinary agar and incubated for 24 hours. The preparation was then 

 placed under a Microscope and the sporoblasts fished out with a platinum 

 wire. The spores were made into an emulsion with bouillon and 



* C.E. Soc. Biol, de Paris, lii. (1900) pp. 1115-7. 



t Tom. cit, pp. 1048-51. J See this Journal, 1900, p. 391. 



§ Brit. Med. Journ., 1901, i. p. 450. || Tom. cit., pp. 448-9. 



