1881.] On Diptera as Spreaders of Disease. 539 
fish, egg-shells, the sweepings out of dog-kennels and hen- 
houses, forming thus, in short, a mixture of evil odour, and 
well adapted for the breeding-place of not a few Diptera. 
The uses to which this “dust” is put when ultimately 
fetched away are surprising : without being freed from its 
organic refuse it is used to fill up hollows in building-ground, 
and even for the repair of roads. A few weeks ago I passed 
along a road which was being treated according to the 
iniquity of Macadam. Over the broken stones had been 
shot, to consolidate them, a complex of ashes, cabbage- 
leaves, egg- and periwinkle-shells, straw, potato-parings, a 
dead kitten (over which a few carrion-flies were hovering), 
and other promiscuous nuisances. The road in question, be 
it remarked, is highly “ respectable,” if not actually fashion- 
able. The houses facing upon it are severely rated, and are 
inhabited chiefly by “ carriage people.” What, then, may 
not be expected in lower districts ? 
Much attention has lately been drawn to the fish-trade of 
London. It has not, however, come out in evidence that the 
fish-retailers, if they find a quantity of their perishable wares 
entering into decomposition, send out late in the evening a 
messenger who, watching his opportunity, throws his burden 
down in some plot of building land, or over a fence. When 
I say that I have seen in one place, close alongside a public 
thoroughfare, a heap of about fifty herrings, in most aCtive 
putrefadion and buzzing with flies, and some days after- 
wards, in another place, some twenty soles, it will be under- 
stood that such nuisances can only be occasioned by dealers. 
To get rid of, or at least greatly diminish, carrion-flies, 
house-flies, and the whole class of winged travellers in 
disease, it will be, before all things, essential to abolish such 
loathsome mal-pradtices. The dust-bins must cease being 
made the receptacle for putrescent and putrescible matter, 
the destruction of which by fire should be insisted upon. 
The banishment of slaughter-houses to some truly rural 
situation, where the blood and offal could be at once utilised, 
would be another step towards depriving flies of their pabu- 
lum in the larva state. An equally important movement 
would be the substitution of steam or electricity for horse- 
power in propelling tram-cars and other passenger carriages, 
with a view to minimise the number of horses kept within 
greater London. Every large stable is a focus of flies. 
2 N 2 
