IOWA ACADEMY OF SCIENCES. 
115 
and 98 per cent and upwards in two weeks. It does not 
seem probable that this organism will retain its vitality 
for a great while in ordinary water. It certainly does not 
propagate. Shortly after the discovery of the agglutinat- 
ing property of B. typhosus by Widal renewed efforts were 
made to detect the typhoid bacillus in water and on the 
strength of these tests several French investigators found 
the bacillus everywhere, in water, in soil, and the faeces of 
healthy individuals.* * * § A German investigator relying on 
this test found the water in certain cisterns infected and 
an Englishman, Hankin,f found it common in the soil and 
other places. Further investigation, however, revealed 
the fact that the colon bacillus is also agglutinated by the 
typhoid serum. It, therefore, appears that so far as these 
tests are concerned that we still need a great deal of in- 
formation on the subject, that we are still somewhat 
uncertain on some points. 
Dr. Vaughan ^ says, “I have never found in drinking 
water a germ that responded to the Wi \i test.” 
For a valuable paper on bacteriological analysis of water 
the paper by Winslow should be consulted. 
The English have used phenolated media.§ “It was at 
one time thought that the addition of .2 per cent carbolic 
acid to the ordinary media inhibited the growth of all 
bacteria but the typhoid bacillus. It has been found, how- 
ever, that the growth of the B. coli is also unaffected by 
such a medium, though it prevents the growth of most 
putrefactive organisms which liquify gelatin.” And 
Hankin, of the British Army Medical Corps in India, uses 
Farietti solution as follows: Four per cent of hydrochloric 
five per cent carbolic acid or phenol. His method is as 
follows: “He adds portions of the water to be tested to 
tubes containing successively increasing proportions of 
Parietti solution. The tubes at the bottom of the series, 
in which the acid is not too strong, become turbid, and 
*Ann. de 1' Inst. Pasteur. 11: 55. 
\ Ontr. Bakt. 26: 554. 
t The Jr. of the Am. Med. Ass. 42:941. 
|| Winslow, 0. E. A. —Bacteriological Analysis of Water and Its Interpretation. New 
Eng. Water Works Assoc. 15 : 470. 
§ Muir & Ritchie. —Manual of Bacteriology. 330. 
