DISINFECTION. 323 
No. 37. Decay of Fruit. Select some sound apples and inoculate them 
with mold spores by dipping the tip of a knife-blade into a mass of mold 
spores of the growths in No. 34 and thrusting the tip through the skin of 
the apple. It will be best to inoculate different apples with each of the 
kinds of mold that have grown on the objects in No. 34, some of which 
will probably be the species to produce decay. Place the apples in a fruit 
jar, close the mouth, not too tightly, and set aside in a warm place. Ex- 
amine day by day and note that decay soon begins, starting at the inocu- 
lated points. Allow the decay to continue till the mold breaks through 
the surface and produces spores. If decay does not occur, it means that 
the species of mold used were not those that produce decay, and the 
experiment should be repeated with molds from other sources. 
DISINFECTION. 
No. 38. Disinfectants. Of the many disinfectants in use three are of 
particular practical value. These, in the strength commonly used, are the 
following: 
Carbolic Acid Solution, 120. 
Carbolic acid crystals, 2 5 grams 
Water, 500 c.c. 
In weighing the crystals of carbolic care should be taken not to touch 
them with the fingers since they will burn the skin. 
Corrosive Sublimate Solution, i 1000. 
Corrosive sublimate, i gram 
Water, 1000 c.c. 
In making and handling these solutions it should be borne in mind that 
they are very poisonous. 
Chlorid of Lime. 
Fresh chlorid of lime, 2 5 grams 
Water, 500 c.c. 
This disinfectant is cheap and effective if fresh, but it will not keep, 
and should be made up at the time of using. One pound of the chlorid 
of lime in six gallons of water will make up an efficient, cheap disinfectant 
for disinfecting walls and floors of rooms and has the advantage of being 
non-poisonous. 
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; b. 1/4 gram salt; c. i gram salt; d. 2 grams sugar; e. 5 grams 
sugar;/, one dr op. of corrosive sublimate solution (i-iooo); g, six drops 
of corrosive sublimate solution; h. one drop of formalin; i. three drops 
