670 PROCEEDINGS OF SECTION H. 
disease in Melbourne are great, and the evidence in support of 
it unsatisfactory. i 
As to the part played by contaminated milk in spreading the 
disease, I do not propose to say much. Milk epidemics have 
often been reported, especially in England ; though, in very many 
cases, the evidence that the milk was specifically contaminated, 
and that its use was the sole and efficient cause, was decidedly 
insufficient. If this mode of propagation is at all common in 
Melbourne there could hardly fail to be accumulation of evidence 
of its occurrence. As a matter of fact, however, there has been 
only one such outbreak investigated, and even in that mstance 
there were great difficulties to be accounted for. (‘Transactions 
of the Intercolonial Medical Congress, Vol. IL, p. 159.) After a 
good deal of careful inquiry,’ carried on for a series of years, I 
have been unable to discover a single instance of an outbreak 
produced in that way. 
In how far typhoid may be caused by the inhalation of emana- 
tions from the soil, or from cesspits or drains, it is difficult to 
determine with certainty. Among English authorities generally 
there has always been a strong belief in the readiness with which 
the disease is produced by the inhalation of sewer-gas. I am not 
aware that the bacilli of typhoid have been found in the foul air 
escaping from drains or sewers, or in the exhalations from a filth- 
saturated soil. But it has been shown by Dr. J. D. Robertson 
(British Medical Journal, 15th December, 1888) not only that 
under particular conditions large numbers of bacteria escape from 
the openings of sewers, but that bacilli preponderate among them, 
as compared with the micro-organisms in the air of streets. In 
some ways, even more important was the observation of Dr. 
Henry Tomkins (S7itish Medical Journal, 25th August, 1888), 
that in Leicester, which is notorious for the prevalence and 
fatality of summer diarrhea, the air of the diarrhea districts of 
the town contained three to six times as many micro-organisms or 
their germs as the air of the non-affected districts. Meteorological 
observations during the summer months of 1885, 1886, and 1887 
showed that as soon as the earth, at a depth of one foot, reached 
about 62 deg. F. the disease broke out. 
As to the influence of sewer air in producing typhoid, the 
observations of Dr. Alfred Carpenter, of Croydon, are of special 
interest. He states (British Medical Journal, 22nd June, 1889), 
that in three serious epidemics he became convinced that germs 
were conveyed from the sewers by aérial means. He quotes, also, 
the demonstration by Dr. Buchanan of the reason why fever 
existed on one side of two or three streets and not on the other, 
in which the water supply being the same and the sewer the same. 
In the one set of cases the air was admitted into the houses from 
the sewer, in the other it was not. 
My own observations have led me to the conviction that, in 
