286 Manual of Veterinary Mlcrohiology. 



In young cultures the latter form also predomi- 

 nates. 



Action of 'physical and chemical agents. — The spores 

 are very resistant to heat ; they support a tempera- 

 ture of 80° during six hours, or 90° during one hour. 

 In moist heat at 100° they are killed in a quarter of 

 an hour, at 115° in five minutes. Spores which are 

 thoroughly dried retain their vitality for a long time 

 if protected from the light. Exposed to the light 

 they do not survive more than one month especially 

 if, at the same time, exposed to the air. 



The bacilli of Nicolaier are little sensitive to the 

 action of antiseptics, notably less so than the septic 

 vibrio. Thus, sublimate solution, at 1 to 1000, only 

 kills these bacilli after three hours; three per cent 

 carbolic acid solution after ten hours. The spores re- 

 sist a five per cent solution of carbolic acid for fifteen 

 hours, the same solution with an addition of 0*5 per 

 cSnt of hydrochloric acid, two hours, and 1 to 1000 

 sublimate solution with a like proportion of hydro- 

 chloric acid, thirty minutes. They are unafltected by 

 the gastric juice and by putrefaction; active cultures 

 having been administered to rabbits, guinea pigs, mice 

 and dogs by way of the mouth, all these animals re- 

 mained healthy, whilst their excrements were virulent 

 for other animals. 



Cultures. — The bacillus of Nicolaier vegetates in 

 artificial culture media when the oxygen of the air is 

 excluded and when under suitable conditions of tem- 

 perature; culture vessels should therefore be em- 

 ployed in which a vacuum has been created or in 

 which the atmosphere has been replaced by hydro- 

 gen, carbonic acid, etc. Solid liquetiable media, such 



