348 LABORATORY WORK 
No. 39. Testing Disinfectants——-Mix the white of an egg with ten times its 
bulk of water, and place the material in a series of test-tubes filling each about one- 
third full. To the different tubes add the following: (a) no addition; (0), 44 gram 
salt; (c) x gram salt; (d) 2 grams sugar; (e) 5 grams sugar; (f) one drop of corrosive 
sublimate solution (1—1,000); (g) six drops of corrosive sublimate solution; (/) one 
drop of formalin; (¢) three drops of formalin; (7) one drop of carbolic acid solution 
(s-20); (2) four drops of carbolic solution; (2) ten drops of carbolic solution; (m) 1/8 
gram of borax; () 144 gram of borax. Place all test-tubes in the incubating oven 
and examine at intervals to see which of them undergo putrefaction and which are 
thoroughly disinfected. Note how very much more efficient some disinfectants 
are than others. Which proves to be the most efficient? It is well in this ex- 
periment to close the tubes loosely with a cork to prevent evaporation of the 
volatile disinfectants. 
The Use of Disinfectants——The ordinary use of disinfectants is in connection 
with disease, their purpose being to destroy disease germs and thus to prevent the 
spreading of disease. They are sometimes used for other purposes, such as reducing 
offensive odors, etc., but primarily they are for the checking of infection. There are 
various methods of killing bacteria which may be applied under different conditions. 
Heat, sunlight, drying, chemicals, and disinfecting gases are all of use in certain con- 
nections. The determination of which is to be used will depend upon conditions. 
The first problem to be settled in all cases of disinfection is when and where the dis- 
infecting agent should be applied to produce the desired results. A few practical 
suggestions as to methods may be of value. 
The Person.—Of all sources of danger the one of greatest importance is the 
person; first the palient, especially after recovery, when he is to mingle with other 
people, and secondly the attendants on the patient. Disinfection of the patient dur- 
ing the disease is rarely possible, though his skin should be kept clean by bathing in 
water to which a little glycerin is added. The nurse, however, should keep scrupu- 
lously clean. Her hands should be carefully washed in soap and water followed by 
strong alcohol, or the corrosive sublimate solution above described. Such cleaning 
should follow every time that the nurse handles the patient or any article of clothing 
or eating utensils touched by the patient. Other parts of the body also need 
attention, but not so frequently. The hair should be kept in a cap to prevent its 
getting contaminated, for it is difficult to clean and almost impossible to sterilize 
it. When the patient has recovered so as to leave quarantine he should receive the 
same treatment. 
Carbolic acid solution is especially useful as a skin wash, and is extremely valuable 
in cases of cuts or skin abrasions. If all cuts and bruises be washed at once in the 
carbolic solution (149), many a serious sore and many a case of blood poisoning will 
be prevented. Every household should have a carbolic acid solution on hand for 
such purposes. 
Clothing, Bedding, Etc.—These articles offer a difficult problem. The following 
general directions may be given. 
Burn everything which is of no great value. 
