LONGEVITY OF B. TYPHOSUS OUTSIDE OF HUMAN BODY. 187 
Little detailed material is at hand concerning other kinds of food, 
but Hesse (1889) working vdth sterilized food-stuffs found that 21 
out of 30 were good media for the development of typhoid bacilli. 
Viahility on fahncs, clothing, etc . — Parkes (1903) cites a case of 
natural occurrence controlled bacteriolos^icallv, which shows that 
B. typhosus may remain viable and virulent on blankets for six 
months. These blankets, last used in military service in South 
Africa, were sold under emergency vdthout having been cleaned, 
and some of them found their way to the training ship Cornwall in 
the Thames. Am outbreak of typhoid occurring on the ship, some of 
the blankets from the lot received from South Africa were sent to 
Klein for bacteriological examination, and he found the B. t}'y>hosus 
to be present. The period of time from the use of these blankets to 
the finding of the bacillus was about six months. Firth and Hor- 
rocks (1902) give the follovdng results of their observations upon 
fabrics. On khaki inoculated 'with an emulsion of typhoid bacilli, 
dried and kept at an average temperature of 54° F., the organism 
lived seventy-four days. On khaki and blue serge similarly treated 
it lived eighty-seven days. On khaki drill infected with liquid stools 
and kept at an average temperature of 61° F. it lived only seventeen 
days, and when dry stools were used for inoculation it lived but nine 
days. Pfuhl (1902) says that dried on linen it lived ninety-seven 
days, while Billings and Peckham (1895) state that dried on threads 
and kept dry in vacuo it was still living after two hundred and 
seven days and kept over sulphuric acid after two hundred and 
thirteen days. 
Insects . — The agency of insects in transmitting t^'phoid is well 
known from epidemiological observations, and this is also demon- 
strable bacteriologically, at least for flies. Firth and Horrocks have 
shown that flies may carry the bacillus and infect media, and give 
evidence that the external parts and not the excreta harbor it. 
• Hamilton (1903) captured flies which had visited typhoid dejecta in a 
sewer traversing an infected neighborhood and demonstrated that thev 
carried the bacillus. Ficker (1902-3) attempted to determine how long 
the bacillus could live on flies infected from blotting paper soaked in 
bouillon culture, and found that it could survive for at least twenty- 
three days. Howard (1900) states that he found 77 species of diptera 
on feces, of which number 36 bred therein. He also states that the 
house fly does breed in human feces, although preferring horse dung 
for that purpose. 
The following list of references to articles having more or less bear- 
ing upon the longevity of B. typhosus is appended for the use of those 
who wish to consult the original sources. Articles referred to in the 
foregoing resume are indicated by an asterisk. 
