80 BACTERIAL DISEASES OF PLANTS 



last traces of air quickly from rather large spaces the Langmuir 

 Condensation High-vacuum mercury pump is highl}^ recom- 

 mended. This requires a rather large opening and the initial 

 vacuum must be made by means of another pump. Very 

 recently "A New Cenco High Vacuum Pump" has been adver- 

 tised as accomplishing quickly the removal of air from consider- 

 able spaces, down to 0.001 mm. without the aid of an accessory 

 pump (Science, n.s., Oct. 3, 1919, page x). Its dimensions are: 

 length 32 in., width 11 in., height 18 in. Strong claims are also 

 made for "The Gramercy Rotary High Vacuum Pump" 

 {Science n. s., Dec. 26, 1919 (Cover). 



Titration Apparatus. — See Sutton's ''Volumetric Analysis." 

 Blood Serum and Starch Media Oven. — See the Text books. 

 Miscellaneous. — Grinders, shakers, meat-presses, knives, 

 forceps, shears, graduates, beakers, ring-stands, Bunsen burners, 

 cork-borers, glass tubing, copper wire and many other small 

 articles add to the convenience of the laboratory which should 

 be supplied with gas, electricity, hot and cold water, and ice, all 

 ir abundance. 



2. For Isolation and Care of Cultures 



Tools. — For isolation of bacteria from plant tissues very 

 simple devices are all that is required, viz., steel needles in bone 

 or wooden handles, small forceps, spatulas, platinum-iridium 

 needles and loops, small knives, scissors, pipettes, glass-tubing, 

 rubber-tubing, sterile Petri dishes, test tubes and flasks, a gas 

 burner or alcohol lamp, sterile water or bouillon for diluting, and 

 suitable culture media. To these may be added large resist- 

 ant glass bottles for holding distilled water and stock solutions 

 of the standard germicides — especially mercuric chlorid and 

 carbolic acid. 



Culture Chambers. — Isolations may be made in clean open 

 rooms if air currents are excluded, but it is safer to work under a 

 small hood or in a special culture chamber from which the indif- 

 ferent and the unclean are carefully excluded. In the Depart- 

 ment of Agriculture we use a special standard culture chamber 

 made in sections in Baltimore by Ruse and Co., at a cost singl}' 

 of $130^(pre-war price). These are well lighted, of convenient 



