The Laboratory 69 



boards, and possibly an Arnold sterilizer. Gas, 

 vacuum for use in filtering, compressed air for use 

 in drying pipettes, etc., and extra water connec- 

 tions and electric outlets should be provided. The 

 stove, autoclave, and oven require no special com- 

 ment. The sink should be of acid-proof vitreous 

 material with vitreous piping, or should be kept 

 thoroughly paraffined since a great deal of wash- 

 ing in chromic acid cleaning solution will have to 

 be done therein. It should be fairly large, with 

 the faucets placed high enough to escape possible 

 splashing from the sink. It has been found con- 

 venient to place a broad shelf above the sink wide 

 enough to take two 20-liter Pyrex carboys, one for 

 single-distilled water, the other for double-dis- 

 tilled water, and to drain graduates from a rack 

 below the shelf. There should also be a draining 

 rack for flasks and miscellaneous glassware. If 

 distilled water is available as a laboratory service, 

 it can be piped above the sink and replace the 

 carboy of single-distilled water. Such a supply 

 should not, however, be relied upon for water for 

 making up solutions or for the final rinsing of 

 glassware. For these purposes, water should al- 

 ways be re-distilled in a special still installed in 

 the media room. Where a laboratory supply of 

 distilled water is not available, it will be necessary 

 to have two stills, either separate or built in tan- 



