PREVENTIVE MEDICINE 201 



doubt if subjected to a good flaming, and no harm is done to them. 

 Stall partitions, mangers, and other fittings can be flamed with the 

 lamp, and the heat can be made to penetrate into all the cracks and 

 crevises without damaging the material. Many other instances of 

 the practical utility of the flame could be given. 



MOIST HEAT. Moist heat is used as hot water, moist air, and 

 steam. 



Hot Water. The momentary application of boiling water to 

 germ-carrying articles is not disinfection, but if such articles can 

 withstand actually being boiled for twenty minutes or so, then 

 disinfection does occur. With ordinary atmospheric pressure the 

 spores of pathogenic bacteria are killed off in about ten minutes, but 

 boiling an article for ten minutes or thereby is quite another matter 

 from the passing application of boiling water. When boiling water 

 is used for the scouring out of mangers and similar stable fittings 

 this must not be regarded as having any germicidal action. In the 

 first place the period of contact is much too brief, and, in the second 

 place, though the water may be boiling when put into the bucket it 

 soon cools, and by the time it has come in actual contact with the 

 manger or travise it is many degrees below boiling point. The 

 application of hot water, especially if it contains soda, is, however, 

 very useful owing to its cleansing action. The scalding of fittings, 

 &c., should be looked upon as an adjunct to disinfection proper. In 

 some instances, as when anthrax blood is spilled on a byre floor or 

 on a travise, such preliminary scalding is contraindicated. The 

 blood must be made harmless before it is removed. 



Some articles of clothing can stand being boiled, but the boiling 

 fixes such stains as blood, and tends to spoil the appearance of the 

 goods. 



The boiling of metal articles such as surgical instruments 

 has for long been the recognised method of effecting sterilisa- 

 tion. The rusting of metal that sometimes occurs can be pre- 

 vented by boiling the water for some time previous to immersion 

 of the articles. 



Water boils at 212 F. at sea level, that is with a barometric 

 pressure of 30 inches. The lower the atmospheric pressure the 

 lower is the " boiling point," so that boiling water at a level much 

 above that of the sea would not have the same potency as a bacteri- 

 cide as it would on a lower level with a higher air pressure. 

 Conversely, the higher the air pressure the higher is the boiling 

 point, thus water boils at 249 F. when the pressure equals two 

 atmospheres or 30 Ibs. to the square inch. Water containing a 

 saline such as calcium chloride or carbonate of soda also boils at a 



