TWELFTH ANNUAL YEAR BOOK— PART X 501 



DETAILS OF DISINFECTION. 



In the practical work of disinfection there are three essentials: 



1. A pieparation of the building that will facilitate reaching organisms 

 of disease. 



2. A disinfectant which upon contact can be depended upon to des- 

 troy such organisms. 



3. A method of applying the disinfectant that will assure the most 

 thorough contact with the bacteria. 



PBEPAKATION OF BUILDING. 



Before beginning .the use of a disinfectant it is essential that cer- 

 tain preliminary work be done in and about the stable that is to be 

 treated. The various surfaces, such as ceil.ng, walls, partitions, floors, 

 etc, should be swept until tree Irom cobwebs and dust. Any accuinuia- 

 tion of tilth should be removed by scraping. In some casts the wood- 

 work may have become softened and so porous as to be a good meuium 

 for the absorption of diiease germs. Such woodwork should be removed, 

 burned, and replaced with new mateiial. 



All refuse, manure, etc., from stable and barnyand should be removed 

 to a place inaccess.ble to live stock and, if pcssiule, be buined or thor- 

 oughly mixed with a solution of chloiid of lime in the proportion of 6 

 ounces to 1 gallon of water. If the floor is of earth, it will doubtless 

 have become sta.ned with urine and contaminated to a depth of several 

 inches. In such cases 4 inches or more of the surface soil should be re- 

 moved and treated as above suggested for retuse and excreta. All earth 

 removed should be replaced with soil fiom an uncontaminated source, or 

 better, a new floor of concrete may be laid, this being the most durable 

 and sanitaiy material for the purpose. 



SELECriON AND PBEPAKATION OF THE DISINFECTANT. 



Having made ready the field of operation, the next consideration should 

 be the selection and preparation of the disinfectant. The fact must not 

 be overlooked that many agents used for the destruction of Lacteria are 

 likewise poisonous to animals and man. In fact, some drugs, although 

 powerful as germicides, are so poisonous as to preclude their general use 

 in the work of disinfection. Among such, as previously slated, is bi- 

 chloiid of mercury, which pcssessts the power of destroying not only the 

 bacteria, but spores as well. It is therefore essential in deciding upon 

 an agent to select one having a known germicidal strength, properties 

 of solubility, and at the same time possessing a reasonable degree of 

 salety to animals and man. 



All things considered, it is probable that some of the coal-tar products 

 best fulfill these requirments. In this class is the compound solution of 

 cresol, already mentioned, a preparation recognized as oiTicial by the United 

 States Pharmacopoeia and known as liquor cresolis compositus {U. S. P.). 

 This preparation mixes readily with water and will prove a very efficient 

 disinfectant. It should be used in the proportion of 4 or 5 ounces to 

 each gallon of water. 



