110 Dairy Bacteriology. 



The direct rays of the sun have a powerful disinfecting 

 -action, and light makes evident accumulations of dirt 

 that in a darker room would be unnoticed. Ventilation 

 keeps the rooms dry and thus prevents the growth of 

 mold and the development of a musty odor. 



Disinfectants are divided into two classes: (1) solid 

 materials used in suspension, or in watery solutions; (2) 

 gaseous substances. The latter are preferable for room 

 disinfection when their use is permissible, for the gas 

 penetrates to every part of the space, even into the 

 cracks. Gaseous disinfectants can only be used when the 

 space is tightly closed, for the gas must be confined for 

 several hours in the room, in order to make the process 

 effective. Such disinfectants can often be used to ad- 

 vantage in the treatment of refrigerators and cheese 

 rooms to destroy mold spores. In less tightly closed 

 spaces, reliance must be placed on the use of the solid or 

 liquid disinfectants. 



Lime. Quick lime or stone lime has a considerable 

 disinfecting action. On exposure to the air, quick lime 

 becomes air slaked, and then has no disinfecting action 

 whatever. Water-slaked lime used in the form of white 

 wash, lime water, or the powder is effective. Air-slaked 

 and water-slaked lime are similar in appearance, but a 

 difference can be noted by placing a particle of each on 

 the tongue; the air-slaked tastes like chalk while the 

 water-slaked material causes the tongue to burn. 



White wash is one of the most effective agents that 

 can be used in the disinfection of barns, milkrooms, etc. 

 Besides being a fairly strong disinfectant, it has a ten- 

 dency to absorb odor, it encrusts the walls and lightens 

 the interior of rooms. It can be applied with a brush or 

 with r, spray pump. 



