DISPOSAL OF INFECTIOUS MATERIAL. 



107 



stances likely to become moldy must never be stored in refrigerators designed for 

 pure cultures. The open ice-box is the proper place for such substances, and they 

 must not be left there indefinitely. Some people have a mania for collecting every- 

 thing and then keeping it a long time without making any use of it. An ice-box 

 treated in this way soon becomes an intolerable nuisance. 



Discarded plates, tubes, slides, covers, pipettes, contaminated litmus paper, etc., 

 should be autoclaved, or covered or filled with cleaning mixture, or dropped into it, 

 as the case may be. Deep, narrow glass jars or long, rectangular enameled pans are 

 necessary for the pipettes. Soiled hands may be disinfected with mercuric-chloride 

 water (1:1000), which should always be on hand in the laboratory in quantity prop- 

 erly labeled. Slight wounds should be washed five or 

 ten minutes in this fluid. Surfaces of floors, tables, etc. 

 soiled by spilled bacterial cultures should be covered 

 immediately with mercuric-chloride water (1:1000) and 

 wiped up carefully after ten or fifteen minutes with 

 distilled water. Spilled cultures of molds should be 

 soaked in mercuric chloride ( i : 1000) for at least an hour 

 before wiping up. Neglect of these simple rules means 

 the seeding down of the ice-boxes, culture-chambers, 

 and the general laboratory with all sorts of resistant 

 mold spores and bacteria. An abundance of cheap car- 

 bonate of lime should be kept on hand for the prompt 

 neutralization of spilled acids. A mass of cotton waste 

 is convenient for the prompt mopping up of spilled 

 fluids. 



All contaminated needles, loops, knives, scissors, 

 forceps, etc., may be sterilized in the open flame. 

 Instruments which are too valuable to be flamed may 

 be sterilized in carbolic acid (5 per cent) or formal- 

 dehyd (5 per cent) or lysol (5 per cent). Never put 

 down a platinum needle or loop which has been used 



Fig, 92* 



in making transfers until it has been passed carefully its whole length through the 

 flame. Dissections are best made on trays which can be easily cleaned and sterilized. 



*Fic. 92. Compressed-air tank and spray-tube. The one here shown, made by Boeckel, Phila- 

 delphia, is nickel-plated and very substantially constructed. It is filled by means of a small pump 

 similar to a bicycle pump. The gage registers up to 100 pounds per square inch, but 40 pounds 

 pressure is ample. The bacterial fluid is placed in atomizers of the form shown in fig. 93. The 

 method of attachment is not satisfactory. This device is very convenient when trees or low plants 

 covering a considerable area are to be inoculated. Height, 29 inches. The same firm has devised 

 a compact traveling outfit, the compressed-air tank being about one-half the size of the one here 

 figured. The whole is packed into a neat portable box, and the only disadvantage is the small size 

 of the air-chamber, which requires more frequent pumpings. Of course the apparatus may be used 

 equally well for the distribution of fluid germicides or insecticides. 



