[156] Corfield.
It is said that in the working of any of the above processes, little or no nuisance ensues, if only ordinary care and intelligence are used. In many cases the excreta collected by the methods above specified is conveyed to manufactories and then converted into manure.
It does not appear that in England the health of the workmen employed in a manure manufactory or of those who live in the neighbourhood of it suffers in consequence.
Removal of the excreta after treatment with deodorising and antiputrescent substances. This is the method usually adopted when the dry process is followed; the excreta mixed with the deodorising substance when removed from the house being at once applied to the land.
a. Coal and wood ashes. It is a common practice in the north of England to throw coal ashes on the excreta, which fall into closets made with hinged flaps or seats for the purpose of admitting the ashes, as at Manchester and Salford. Wood ashes are far more effective deodorisers than coal ashes, but they are seldom procurable. “In some towns there are receptacles called ‘middens,’ intended both for excreta and ashes; sometimes these are cemented, and there may be a pipe leading into a sewer so as to dry them. The midden system is a bad one; even with every care, the vast heaps of putrefying material which accumulate in some of our towns must have a very serious influence on the health, and the sooner the middens are abolished the better.”[157]
[157] Parkes.
b. Deodorising powders. At some of the Indian stations deodorants, such as M’Dougall’s, or Calvert’s carbolic acid powders, have been successfully employed, a comparatively small quantity being mixed with the excreta.
In Germany a mixture of lime, chloride of magnesium, and tar is largely used for the
same purpose, and is known as Süverns’ deodoriser.”
Another deodoriser (the Müller Schür), also used in the dry method, is composed of lime, 100 lbs.; powdered wood charcoal 20 lbs.; peat powder or sawdust, 10 lbs.; and carbolic acid (containing 60 to 70 per cent. of real acid) 1 lb. After having been mixed, the mass is placed under cover for a night to avoid any chance of spontaneous ignition, and when dry it is packed in barrels.