March, 1907.] The Public Drinking Cup. 105 



was redissolved to make the results unreliable, hence all notes 

 should be made as soon as the tests are completed. 



It is also possible to add an excess of silver nitrate, when 

 testing the solution, and if this is done a slight precipitate may 

 be redissolved and inaccurate results obtained. 



Summary of Results. 



In drawing conclusions as to the rapidity with which the gas 

 will diffuse to different parts of the fumigating box, it should be 

 borne in mind that this will depend somewhat on the violence of 

 the reaction, which will probably differ slightly in every test on 

 account of differences in size in the lumps of cyanide used, the 

 depth to which they are submerged, and the thickness of the 

 paper which is used for wrapping. 



In an empty box the gas diffused very rapidly, as is shown in 

 tests one and two, every sample taken indicating its presence. 

 Equally good results were secured when the floor of the empty 

 box was drenched with water. 



In the case of the box that was packed with stock it appeared 

 that the diffusion was retarded, but reactions were secured, 

 showing the presence of the gas in all the samples drawn in the 

 longer periods. Very similar results were secured in both tests, 

 and as far as the data in the experiment goes, no difference in 

 result was noted, whether the temperature was normal (72°), or 

 at the freezing point (32°). 



From the results of test seven it appears that it is not desir- 

 able to fumigate stock that is drenched with water, although in 

 this test a trace of the gas was found in each sample drawn. 



Columbus, Ohio. 



THE PUBLIC DRINKING CUP.* 

 Bacteriological Report, 



Eugene F. McCampbell. 



It was suggested long ago that the public drinking fountain 

 with its chained cups is decidedly unsanitary but few investiga- 

 tions are on record to prove this point scientifically. In the 

 hope of adding something to the somewhat indefinite knowledge 

 and to find out if possible exactly what objectionable species of 

 bacteria were present, we made a series of ten bacteriological 

 examinations of drinking cups from various fountains. In 

 selecting cups for the examinations those which appeared to be 

 decidedly unsanitary as well as those which appeared cleanly 

 and connected with fountains which were used by the higher 

 strata of society were selected. 



* Read before the Ohio State Academy of Science, November, 190G, 

 Columbus, Ohio. 



