174 



SCIENCE. 



[N. S. Vol. I. No. 7. 



1. Forty -five varieties of bacteria found 

 in the water of the Schuylkill river were 

 \ised in the first experiment. Cultures of 

 each organism were made on agar-agar and 

 after attaining a luxuriant growth were 

 sterilized, the reaction was taken, and the 

 medium was again slanted. A set of these 

 tubes was inoculated with the bacillus typhi 

 abdominalis and a second set mth bacillvs 

 coli communis. 



The object of this research was to ascer- 

 tain whether the two organisms would grow 

 on media containing the products of the ac- 

 tivity of water bacteria. The reaction was 

 alkaline in every tube. The bacillus typhi 

 abdominalis and the bacillus coli communis 

 lived in every instance, some showing fairly 

 luxuriant growths, while others were only 

 transparent films. 



2. In the second experiment, thirty-nine 

 varieties of the water bacteria used in the 

 first experiment were inoculated into tubes 

 each containiug 10 cc. of sterilized tap-water 

 and 5 drops of bouillon. Two sets of tubes 

 were made as before, one being inocu^lated 

 with the bacillus typhi abdominalis and the 

 other with the bacillus coli communis. To 

 ascertain whether the two organisms under 

 consideration would multiply in the pres- 

 ence of water bacteria, gelatine plates were 

 made for twelve or more days. Both ba- 

 cilli gave characteristic colonies with each 

 of the water organisms, except two which 

 had apparently an antagonistic effect upon 

 their development. They were both mem- 

 bers of the subtilis gTOup. In other mem- 

 bers of this group this peculiarity was ab- 

 sent. 



The typhoid bacillus in several instances 

 outlived its associate organism. In one 

 instance a gelatine plate made from a tube 

 of sterilized water inoculated with the ty- 

 phoid bacillus and a water bacterium 160 

 days previously gave characteristic colonies 

 of the bacillus typhi abdominalis. 



3. To meet the objection that might be 



raised to the use of heat for the sterilization 

 of the medium in which the water organ- 

 isms had grown, the opinion having been ad- - 

 vanced that some products of gi'owth are 

 either volatile or rendered inert by high tem- 

 peratures, flasks each containing 70 cc. of 

 bouillon were inoculated with water bacteria 

 and incubated for from 15 to 20 days. The 

 cultures were then filtered through porce- 

 lain, the reaction was taken, and the filti-ate 

 was run into sterilized tubes which were 

 inoculated with the bacillus typhi abdomi- 

 nalis and the baeilhis coli communis and then 

 incubated. In each of the thirteen filtrates 

 inoculated the bacilli grew and multiplied 

 for at least four days. 



John S. Billings. 



Adelaide Waed Peckham. 



CUMBENT NOTES ON PHYSIOGRAPHY (Z ). 

 INTRODUCTORY NOTE. 



It is proposed to contribute to Science 

 under the above title a series of notes and 

 comments on recent investigations and cm*- 

 rent literature concerning phj^siography, or 

 physical geography in its modern form. A 

 brief statement of the field to be covered 

 may be appropriate at the outset. 



Following the plan inti'oduced by Carl 

 Bitter, and popularized in this countiy 

 chiefly by Arnold Guj^ot, geographj' maj' be 

 defined as the study of the earth in ^'ts rela- 

 tion to man. Some prefer to extend tliis 

 relation to all forms of life. Physical geog- 

 raphy ma J' then be defined as the rational 

 study of those features of the earth which 

 must be understood in order to appreciate 

 its relation to man. In deference to the 

 opinions of the majority of the conference 

 on geographj^, held in Chicago in Christmas 

 week, 1892, physiography is taken as the 

 name of this subject in its modern form, 

 with particular reference to the rational 

 study of the lands, where man dwells. De- 

 scr'iptive geography is an empirical study 



