A no less serious evil is the corrosion of lead traps or lead waste-pipes, particularly in old houses which have unventilated drains. This may he caused by the action of sewer-gas, so called, or from the use of certain popular disinfecting fluids.
Lengths of pipe have been found completely honey-combed in this way. As such corrosion usually occurs on the upper side of traps or horizontal pipes, it is not easy to detect their presence from the absence of leakage, and the only safeguard is to avoid carrying waste or soil pipes horizontally; also, to extend their upper ends through the roof, and leave them open for ventilation. Lastly, to substitute iron pipes for lead wherever possible, which is now the general rule in all good plumbing practice. . . . Corrosion sometimes occurs at the joints of lead pipes, contiguous to the line of solder, and is attributed to galvanic action created by the contact of the zinc and lead, but as these openings are apt to leak they are more liable to discovery.
It is a good plan to overhaul all plumbing periodically, say once every year or two, to guard against accidents. . . . And here it should be remarked that sewer-gas is created not in the sewers alone, but every inch of waste-pipe in a house, even though used to convey nothing but soapy water or the waste of melted ice from a refrigerator, can, and commonly does, produce foul gases. The worst odors are from just such sources, and they are certainly unwholesome.Moreover, it must always be remembered that no plumber's work, however complete it may be at first, can be relied upon to remain perfect. ("Medical News and Abstract," November, 1881.)
Says Mr. Collins, in "The Sanitary Record," London, for March 15, 1882:
The best plumbing will not, the experts say, last "for ever"; but, in order to render our houses perfectly safe, it ought to last as long as the house will last, for we can in no other way know when the danger is upon us. "It will not last that period of for ever—a few years," says Mr. Collins; and Mr. Wingate says it should be "overhauled every year to two, to guard against accidents." Mr. Wingate has told us what he means by "overhauling" the plumbing, when he said to the Academy that no inspection of the plumbing of a house was of value unless it was overhauled from top to bottom. In no other way could he give the occupant a guarantee that all was right; because, where one defect was found, the chances were that there were many. This, we are then given to understand, is what should be done "every year or two."
But we may be permitted to ask why the time should be fixed at a year or two? A leak might arise from any one of the many causes enumerated to-day, which did not exist yesterday. Why, then, "to