Apsil 8, 1910] 



SCIENCE 



555 



alkali does not seem to be the controlling element 

 in the nitrification processes, and judging by the 

 innocuous action of gypsum it seems evident that 

 in these regions black alkali is not suiEciently 

 abxmdant to be an important factor. In the 

 deeper layers of the most unproductive soils a 

 peculiar fungus is very prevalent and is probably 

 associaied with the failure of this soil to produce 

 crops. 



Desiccated Culture Media: W. D. Fbost, Univer- 

 sity of Wisconsin. 



In order to overcome the generally recognized 

 faults of bacterial culture media, such as varia- 

 tion in the composition of small batches, time 

 consumed in preparation, rapidity with which it 

 deteriorates, and its unavailability in small insti- 

 tutions or private practise, the preparation of 

 culture media in large batches in establishments 

 especially equipped for it and then desiccated, is 



The author's work on this problem, covering 

 nearly a decade of time, is considered and samples 

 are submitted. 



There is, apparently, no reason why the dif- 

 ferent culture media can not be put upon the 

 market in a form which requires merely the addi- 

 tion of water and sterilization to make it ready 

 for use. Not only the ordinary, but probably 

 most of the special media, can be prepared in this 

 way and could be put up, where desired, in the 

 form of tablets, these to be of such a size that 

 they could be put directly into test tubes, and 

 when the proper amount of water is added they 

 would be ready for sterilization and use. 



Laboratory Desks for Students in Bacteriology : 

 W. D. Feost, University of Wisconsin. 

 A laboratory desk is described for use in stu- 

 dent laboratories for which it is claimed that the 

 maximum number of students can be accommo- 

 dated in given quarters with, probably, the mini- 

 mum of confusion. The desk is similar to those 

 used in chemistry, without the shelf above it. It 

 is provided with a wide trough running the full 

 length, which serves as a sink and over which gas 

 hot plates are placed to be used in cooking and 

 sterilization. Each place is provided with three 

 lockers which can be used by as many different 

 students. The reagent shelves are provided for 

 and a shelf for rough weighing at one end, and 

 at the other end the hot-air sterilizer and auto- 

 clave. Microscopical work can be done at each 

 place by using artificial light, or at small window 

 desks, provided for separately. 



An Inexpensive Incuiator Room: W. D. Feost, 



University of Wisconsin. 



A small room is used and maintained at a 

 satisfactorily constant temperature without other 

 change than the attachment to the steam radiator 

 of a thermo-regulator designed for residences. 

 The cost was about thirty dollars, and, with 

 proper shelving, the room will accommodate sev- 

 eral hundred students. An arrangement of lock- 

 ers is also suggested which largely removes the 

 temptation of students to appropriate cultures not 

 belonging to them. 

 The Absolute Relation of B. coli to Oxygen: 



F. G. Keyes, Brown University. 



The absolute relation of gaseous oxygen to the 

 growth and gas production of B. coli promises to 

 be somewhat complicated. 



In a study of the absolute gas production of 

 B. coli in vacuo,* it was found that the gas evolved 

 from a 1 per cent, asparagin, 0.2 per cent, di- 

 sodium phosphate, 1 per cent, dextrose medium 

 began to fall off very decidedly after 115 hours, 

 but the gas evolved was constant in composition. 



In the presence of pure oxygen, no other gas 

 being present, it is found that the rate of evolu- 

 tion of gas is much smaller, but gas production 

 continues for a much greater length of time. The 

 composition of the evolved gas is different when 

 the organism is grown in the presence of oxygen 

 from what it is in vacuo. The composition of the 

 gas depends to a certain extent upon whether the 

 medium is neutralized or not. Some oxygen is 

 absorbed by the growth of the organism in the 

 medium. 



The tables below summarize the results of the 

 experiments. 

 The Absolute Gas Production of B. Typhosus: . 



L. J. Gillespie, Brown University. 



While attempts were being made to find a syn- 

 thetic medium suitable for the growth of B. ty- 

 phosus and such as to facilitate a comparison 

 with the gas production of B. coli, preliminary 

 experiments were made using a medium contain- 

 ing Witte's peptone. B. typhosus was grown on 

 a neutral medium containing 1 per cent, dextrose 

 and 1 per cent, peptone; and the gas evolved, 

 obtained by the procedure given by Dr. F. G. 

 Keyes, was analyzed. The amount of gas found 

 was so small that analyses with the ordinary 

 100 c.em. gas burette and gas pipettes were car- 

 ried out with difficulty. The analyses indicated, 

 however, the following results for 48 hours' 

 growth : 



*Jour. Med. Res., 16, 1909, 69. 



