TYPHOID BACILLUS. This bacillus, the cause of typhoid fever, was first discovered by Eberth in 1880. He found it in the glands of the mesentery and in the spleen. It was not until 1884, however, that Gaffky obtained the organism in pure culture. He first used a potato culture-medium and was fortunate in dhtaining the organism, for since its discovery it is be coming more and more evident that the typhoid bacillus is very closely allied to a great variety of other forms and it is now necessary to use a very complicated technique in order to separate this form from a number of allies. One form, the Bacillus coli commune, or colon bacillus, a constant inhabitant of the intestinal canal, re sembles the typhoid bacillus so closely that as late as 1890 no less an authority than Koch de clared that a sure means of differentiation be tween the typhoid and colon bacillus had not been discovered. Since then, however, work by a number of bacteriologists, Pfeffer, Wasser mann, Loiller,. Abel, Hiss and others, has given a series of distinguishing signs, so that at the present time it is possible, to make a definite separation of the typhoid organism from all others. The typhoid bacillus is a short compara tively plump rod varying in length from IT to of an inch and in width from gu irg to a of an inch. It has a number of flagella (101 to 12) which enable it to move. The marked motility of the typhoid bacillus is of much importance in the study of this form since the so-called blood-test or Widal's test for typhoid depends on a change in this character istic. For the details of its cultural characters standard works on bacteriology should be consulted but it is of importance from the stand point of sanitary science and preventive medi cine (q.v.) to realize that the typhoid bacillus
is capable of growing for a time at least in many different foods and drinks, particularly in milk and in water. Every patient with typhoid fever is constantly giving off millions of these small bacteria in stools and in urine. From these two main sources the great danger in typhoid contagion comes, for soiled fingers of chambermaids, flies, household implements may all.prove intermediaries in conveying the bacilli to food and thence into the digestive canal of a well person. Or the faces and urine may soak into a well or other source of drinking water supply, and thus be the means of causing extensive epidemics. Contagion by uncleanli ness and lack of care in disinfecting the stools and urine is responsible for most cases of typhoid fever. Destroy the bacillus by heat or by proper chemical means and typhoid fever will disappear. (See BACTERIA ; TYPHOID FEVER). Consult Muir and Ritchie, 'Manual of Bac teriology); Kolle and Wassermann, 'Hand buch. der pathogene Mikroorganismen' (1902 04) ; Osier, W., 'Problems of Typhoid Fever in the United States' (Baltimore 1899); id., 'Studies in Typhoid Fevers' (ib. 1895); 'Public Health Report, No. 56' (Washington 1911); 'Reference Handbook of the Medical Sciences' (1915); Whipple, J. G., 'Typhoid Fever: Its Causation, Transmission and Pre vention' (New York 1908).