1885.] 



Studies of Disinfectants by New Methods. 



273 



that the solution equalled 5 per 1000. Weighed drops of this solution 

 were cultivated, and the number of colonies obtained enumerated. 

 According to the mean of four experiments the number per gram of 

 colonies of all kinds in the original typhoid stool was 1,031,250. 



Of these various growths 40 per cent, were forms of mucor and asper- 

 gillus, about 20 percent, were bacilli, bacteria, and micrococci, which, 

 from their manner of growth and general characters, seemed to belong- 

 to common and familiar forms, and were not farther investigated. 



Besides these there were some light brown colonies which grew 

 slowly, the one generally in almost circular spheres, the other in 

 natter irregular wart-like masses ; neither of these growths while 

 cultivated on the thin sheet of gelatin-peptone in the glass cell 

 seemed to liquefy the gelatine, that is, within five or six days of culti- 

 vation, for observation could not be carried on longer than this period, 

 other common organisms, sueh-as B. termo, liquefying the whole mass 

 and mixing up the colonies. It was, therefore, necessary for the 

 farther study of these brown colonies (which might be Gaffky's 

 bacillus) to obtain of each pure cultivations. For this purpose a 

 minute quantity of each was transplanted into a test tube of nutrient 

 gelatin by means of a sterilised platinum wire ; from this cultiva- 

 tion a second was produced, and from the second a third. As the 

 general behaviour of the various cultivations never altered, nor could 

 any foreign element be detected, the last cultivations were considered 

 to be pure, and from these the surface of sterilised slices of potatoes 

 were inoculated. The bacillus, which may be referred to as bacillus (#), 

 and which grew in a more or less spherical manner in the sheet 

 gelatin, when transferred to a test-tube of solid gelatin-peptone, 

 liquefies very slowly the gelatin, growing always in contact with the 

 air. On potato it extends as a dirty scum. The bacilli examined in 

 water showed no power of self-movement. The irregularly growing 

 brown colony, which may be called bacillus (&), also very slowly 

 liquefies the gelatin, but only along the track of the needle. A 

 test-tube cultivation at the end of from fourteen to twenty days has 

 the following appearance. Along the track of the needle there is 

 a cone-shaped perfectly liquid mass. On the surface of the liquid 

 float little detached white-brown colonies ; at the bottom is a white 

 deposit composed of colonies which, having been formed on the 

 surface in contact with the air, have slowly sunk. The liquid inter- 

 vening between the deposit and upper floating colonies is perfectly 

 clear. On potato the bacillus grows rapidly, forming an irregularly- 

 shaped brownish crust, and ultimately presents an appearance very 

 similar to the common wall lichen (Parmelia parietina). 



Whether these bacilli have any connexion with the typhoid state or 

 not, the characters described are quite different from those of Graffky's 

 bacillus. 



T 2 



