IIISI'OSAI, OF INFECTIOL'S MATKRJAJ.. 



w/ 



stances likeh' to Ijecoine moldy must ne\'er Ix- stored in refris^^erators dcsi^-^iied for 

 pure cultures. The open ice-box is the proper place for sucli sulistances, and the)' 

 must not Ije left there indefiniteh'. ,Some people ha\'e a nuinia for collectin.L; e\'ery- 

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

 treated in this waN' stMjn becomes an intolerable nuisance. 



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

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

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

 necessar\- for the pipettes. Soiled hands may l)e disinfected with mercuric-chloride 

 water (1:1000), which should alwa\ s be on hand in the laboratory inquantit}' prop- 



erh' labeled. Slight wounds should Ije washed fi\e or 

 ten minutes in this fluid. vSurfaces of floors, taluks, etc. 

 soiled b)' spilled bacterial cultmes should be co\'ered 

 immediateh' with mercuric-chloride water ( i : ioo( 1) and 

 wiped up carefrdh' after ten or fifteen minutes with 

 distilled water. Spilled cidtures of molds sliould be 

 soaked in mercuric chloride ( 1 : io( " >) for at least an hour 

 )] before wiping up. Neglect of these simple rules means 

 the seeding down of the ice-bo.xes, culture-chandlers, 

 and the general lal)oratory with all sorts of resistant 

 mold spores and bacteria. An a1)undance of cheap car- 

 bonate of lime should be kept on hand for the prompt 

 neutralization of spilled acids. A mass of cotton waste 

 is con\xnient for the prompt mopping up of spilled 

 fluids. 



All contaminated needles, loops, kni\es, scissors, 

 ^^^ forceps, etc., ma)- be sterilized in the open flame. 

 Instruments which are too valuable to be flamed may 

 be sterilized in carbolic acid ( s P<?r cent) or formal- 

 dehyd {5 percent) or Ivsol (5 percent). A^t'z-cT put 

 down a platinum needle or loop which has been nsed 

 in making transfers until it has been passed carefully lis -icliolc length through the 

 flame. Dissections are best made on tra>-s which can be easily cleaned and sterilized. 



Fig, 92.* 



*Fi(;. 1)2. — Coiiipresscil-air tank and .spraN-tubc. The (inc licre shciwn, niailc liy Er.cckfl, Plula- 

 delphia, is nickel-pkitod and very sul)stantially constrnclcd. It is filled liy means of a small pnmp 

 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 atmni/ers of the form shown in fig 93. The 

 method of attachment is not satisfactory. This device is \-cry convenient when trees or low plants 

 co\cring a consideralile area are to be inoculated. Height, 20 inches. The same firm has deviled 

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

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

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

 equally well for the distribution of fluid germicides or insecticides. 



