6 



MEMOIKS OP THE NATIONAL ACADEMY OF SCIENCES. 



Fig. 5. 



may be used for this purpose, or au ordiuary wide-mouthed bottle, fitted with a rubber stopper 

 carrying two tubes, one reaching to the bottom, the other extending only through the stopper, 

 serves the purpose well. In the Centralblatt fur Bakteriologie und Parasitenkunde, for 

 November, 189.'?, Dr. F. G. Novy describes a jar devised by him which embodies this principle, 

 and has been found very satisfactory by him (Fig. 5). Using the same principle, I have designed 

 ajar for what may aptly be termed cultivation "en masse," which has advantages not possessed 



by any other apparatus for the same purpose with 

 which I am acquainted. It fulfills every requirement 

 perfectly, if well constructed, and is easy to operate. 

 The general plan is modeled after the jar used for 

 3 drying gases, known as " Fresenius's Improved " cal- 

 cium chloride jar. It may be purchased of any 

 dealer in laboratory supplies, and even without modi- 

 fication is very useful. The older forms may also be 

 used by fitting rubber corks carrying glass tubes to 

 the month and to the lower opening. 



As adapted to the cultivation of anaerobic bac- 

 teria, the jar is as follows: It consists essentially of 

 a glass cylinder, with a good base, and having some 

 2 inches from the bottom a constriction, dividing it 

 into two chambers which communicate. Opening 

 into the bottom chamber, at the shoulder, is a cor- 

 rugated glass tube, fitted with a well ground stop- 

 cock. The mouth of the jar is large, and fitted with 

 a perforated glass stopper, the perforation opening 

 into the cavity of the jar. A corrugated glass tube 

 is attached to the neck of the jar, through which a 

 hole has been inaile continuous with the perforation of the stopper. By turning the stopper 

 this is closed, sealing the jar at the top. (See Fig. 6.) The jar may be made of different sizes, 

 the following dimensions being most serviceable for general use: Diameter of upper chamber, 

 3 inches; of mouth (inside), 1.5 inches; height of upper chamber (inside, clear of shoulders), 7 

 inches; diameter of lower chamber, 3 inches; height of lower chamber, 2 inches. 



A most essential feature is that the stopper and the stopcock shall be accurately ground, so 

 as to be absolutely air-tight. The height of the upper chamber is adapted to the length of the 

 test tubes one wishes to use, and the diameter to the number of cul- 

 tures most convenient. The use of the apparatus is as follows: A piece 

 of wire gauze is inserted, which rests on the shoulders of the constric- 

 tion, and completes the floor of the upper chamber. On this a layer of 

 cotton is placed. All the media to be used are steamed for fifteen to 

 twenty minutes, and cooled rapidly in ice water. The tubes having been 

 inoculated are then introduced and the jar closed. Into the lower cham- 

 ber is introduced, through the lower tube, an alkaline solution of pyro- 

 gallic acid, enough being put in to fill the chamber up to the opening of 

 the tube. The lower tube is then at once connected with the air pump, 

 and the upper one with a hydrogen generator, the stopper being so 

 turned as to close the jar. When the air has been exhausted, as indi- 

 cated by the vacuum meter, the lower stopcock is closed and the jar filled 

 with hydrogen. The hydrogen is then cut off and the jar again exhausted, 

 and again filled with hydrogen, the process being repeated three times 

 in order to make sure of all the oxygen being removed. The jar is 

 then sealed above and below, and may be put in the incubator if no gelatin has been used. 



The strength of the solution of pyrogallic acid used is one-half that recommended by Buchner 

 for his method, viz, 1 gram of pyrogallic acid to 20 c. c. of a 10 per cent solution of caustic 

 potash. The use of the pyrogallic acid is not necessary if the jars be well constructed, but is 

 employed as a safeguard, and is useful as an indication of the efficiency of the apparatus. 



A 



Fig. 6. — A, jar; B, sectional view 

 of stopper. 



