DISINFECTANTS. ANTISEPTICS 207 



and staphylococci (pasteurization). Anthrax spores withstand 

 boiling temperature. Since the heat only penetrates large, solid 

 objects slowly, it is recommended that the boiling be continued for 

 at least one hour. Boiling water is not a certain disinfectant when 

 used in the disinfection of stables because it cools rapidly when 

 spread out on cold surfaces. In disinfecting by boiling, the water 

 containing the object to be disinfected is placed upon the fire cold 

 and is allowed to remain for at least 3^ hour after boiling begins; 

 the vessel is to be covered. The German veterinary sanitary laws 

 require that when foot-and-mouth disease is present milk shall be 

 disinfected by boiling, and that in the case of tuberculosis it shall 

 be sufficiently heated, i.e., heated over an open fire until it repeat- 

 edly boils, exposed to live steam at 85° C, or heated in a water bath 

 at 85° C. for a minute or at 70° C. for a half hour. The action of 

 hot fluids is especially effective when a disinfectant is added. 



5. Live steam of a temperature of 100° C. is the most effective 

 form of disinfection by heat (sterilizing apparatus) and should 

 therefore be preferred, when convenient, to boiling; has not only 

 a superficial but also a deep action. Anthrax spores and tubercle 

 bacilli are killed in 5 minutes. The best results are obtained with 

 an atmospheric pressure of about one-tenth. It is important that 

 the temperature be not permitted to fall below 100° C, and that 

 an abundant supply of steam be introduced into the apparatus 

 in order that the air (poor heat conductor) will be expressed as 

 completely as possible (apparatuses of Henneberg, Rohrbeck, 

 Lautenschlager, etc.). Disinfection with steam is most suitable 

 for blankets and clothing; on the contrary, leather articles (saddles, 

 girths, halters) are spoiled. Stables, railroad cars and large com- 

 partments in general cannot be disinfected with steam on account 

 of its rapid cooling. In using steam on railroad cars, it was found 

 that the highest temperature of the steam at the outlet tube was 

 90-95° C; slightly removed from the outlet tube (4 inches) the 

 temperature was only 60° C, 40 inches distant 50° C, 80 inches 

 distant 20° C, while 16 to 20 feet distant the temperature was 

 raised only a few degrees (Redard and Colin). A temperature of 

 100° C. cannot be attained in a stable even with steam from 



