MEDIA MAKING AND APPARATUS 279 



the steam rising through the latter. If possible, however, an autoclave should be 

 obtained; one type can be heated directly by gas, making its own steam; the same 

 can be obtained, modified for attachment directly to steam pipes carrying steam 

 underpressure. For laboratory purposes the Bramhall Deane (New York) auto- 

 clave (2B) is highly to be recommended. 



Sterilization in the Arnold sterilizer must be done on three successive days with 

 full steam for twenty minutes each day, the media being kept at room temperature 

 in the intervals between steaming. With the autoclave a single sterilization at 

 fifteen pounds pressure (120 C.) is sufficient. 

 Rubber tubing., white, of a proper size to fit snugly both gas outlets and Bunsen burners. 

 Funnels, ion liter, agate ware, or copper tinned inside, or glass. 

 Granite or agate ware, " double boiler " with cover, capacity of inside pan at least four 



liters. Large granite or agate ware spoons. 

 Wire baskets for test tubes, 7" long, 5" wide, 5" deep, smooth wrapped corners and edges, 



no solder. 

 Petri dishes, with porous tops, 4" diameter, f" to i" deep. 

 Tumblers, to be used with cotton in bottom for holding test tubes ; or wire test tube 



racks, Harvard pattern. 

 Funnels, 2", 4", 6" diameter for filtering stains, etc. 

 Filter paper— (Schleicher & Schull 597) in large squares. 

 Lens paper— Japanese. 



Cylinder graduates — 25 c.c, 50 c.c, 100 ex., 500 c.c, 1000 c.c. 

 Fermentation tubes, Smith pattern, or Hill pattern. 

 Thermometers, for incubator; for oven; for autoclave: for ordinary purposes, say 



6, ranging from 30 C. to no° C, and 2, ranging from 100° C. to 300° C. 

 Cork borer and sharpener. 



Test tube brushes, with sponge at end, bristles at side. 

 Pinch-cocks for rubber tubing. 

 Blast lamp for blowing glass, bending tubes, etc. 

 Stain bottles (1. e., rubber nippled pipette bottles, 1 to 2 oz. capacity. 

 Absorbent cotton, for filtering. 

 Non-absorbent cotton. First grade cotton, for plugging test tubes, etc. ; second grade, for 



tumblers, etc. 

 Fuchsin, basic, Griibler 10 grams Immersion oil. 



Methylene blue " 10 " Glycerine. 



Carbolic acid -phenol -1st grade 1 lb. Canada balsam. 



Aniline oil Griibler 1 oz. Thread agar— best. 



Gentian violet ' " 10 grams Gold label gelatin in sheets— 10 lbs. 



Iodine 10 " Hydrochloric acid 1 lb. 



Potassium iodide I oz. Sodium hydrate 1 lb. 



Alcohol 96% ethyl 1 gal. 



Xylol for cleaning lenses 2 oz. 



Test tubes : 6" x &'', without lip, of good " non-crystallizable glass " (Boston Board of 

 Health pattern) ; they should be plugged with cotton and sterilized in hot air as 

 below. A few test tubes should be graduated and marked at 9. c.c. capacity and kept 

 for dilution purposes. 

 Pipettes : 1 c.c. mark, discharge pipettes, about 10— 11 inches long, 3 mm. inside diameter, 

 are the best. These may be enclosed in long tubes one in each, of glass, sealed at 

 one end, stoppered with cotton at the other ; or the point may rest on a cotton wad 

 at the bottom of a test tube, the mouth of the test tube being plugged with cotton 

 round the stem, a small cotton plug being inserted into the mouth of the pipette 



