View report page

71
disinfectants.
The disinfectants and other chemicals in use in the Public Health Department and in
other branches of the Corporation's service have, as in the past, been supplied under a contract
prepared by your Medical Officer of Health.
They are used for deodorising and denaturising unsound meat, disinfecting public
conveniences, street gulleys, premises after infectious diseases, etc.
Special attention was given to the thoroughfares in the vicinity of the Billingsgate and
Smithfield Markets, the former of which presents certain difficulties in the matter of deodorisation
in the summer months.
Very few complaints were, however, received of offensive odours necessarily associated
with the fish trade.
In the interests of economy the practice of using a disinfectant fluid in conjunction with
general street watering has been discontinued.
rat repression.
Inspections under the Rats and Mice (Destruction) Act, 1919, have been carried out
by Mr. G. A. Webber, one of the Sanitary Inspectors, specially appointed as Rat Officer.
I am again able to report that many satisfactory results have been achieved through
the co-operation of tenants of City Buildings and this Department.
It is not possible to give any indication of the total number of rats caught in the City
during any given period. Messrs. William Dalton & Sons, professional ratcatchers, inform
me that their catch, during 1936, in the City of London, was 16,179 rats, the majority being
Black Rats.
A firm of caterers, with many branches in the City, give their catch, during 1936, as
3,102, and, as in previous years, the majority were Black Rats.
The City has its own particular problem. The conclusions which have been arrived
at, some of which are referred to here, have been gained only by experience in this area,
and many of them should not be taken as applying to the subject generally.
Here we are troubled with two types—the Black Rat and the Brown Rat. These
titles do not give any accurate description of the colour of each specie. It is in formation,
appearance, and habit that they differ. The one is the enemy of the other, and it is not
possible for the two species to interbreed. The Brown Rat is more commonly known as
the Sewer Rat, and is not nearly so widely prevalent now in the City as is the Black Rat.
Nevertheless, it is believed that the Brown Rat is still more generally the country-wide pest,
and this rat's activities were undoubtedly responsible for the introduction of the Rats and
Mice (Destruction) Act, in 1919.
It is the predominance of the Black Rat in the City of London, which, because of its
different habits, renders, to a great extent, the present legislation inadequate and unsuitable
in this area.
The Brown or Sewer Rat is primarily an underground or burrowing animal. Its
presence in a building is often due to a defective drain or sewer in or around the property
it infests, such properties usually being old, and having attached a disused basement or
cellar, whose construction is so defective as to give this rat full scope for its burrowing
propensities. The erection of many new buildings in the City, together with the reconditioning
of old properties, is partly responsible for the reduction in the Sewer Rat population,
and the many regulations which now govern drainage and building construction generally,
particularly in a built-up area, has also had the effect of defeating this rat, without being
drawn up with that particular object in view.
With the gradual lessening of Sewer Rat infestation in the City, the Black Rat has
increased, until it now forms the chief problem, outnumbering its enemy by about twenty
to one at a low estimate. Any grave danger to which the rat exposes the health of humans
is accentuated by the predominance of this Black Rat, because, of the two species, it lives
in much closer relation to mankind.
City buildings, generally, provide excellent homes for this rat, which lives in matchlined
or panelled walls, under floors, in false ceilings, in undisturbed accumulations deposited
k2