Q. I have been asked to try to remove a cause of bad-tasting water from a cooler. My doctor got a plumber to put a 3/8-inch galvan-ized-pipe coil in his ice-box, to be used for drinking-water purposes. The plumber never made one before and was not particular with it, and it tastes badly from oil and lead used in connecting it. The coil is one foot wide, with galvanized elbows. The doctor has the water drawn from the spigot, then placed in a charcoal filterer, and then put in a stone jar, which connects with the coil for use. I have made them before, but was very particular not to use oil in cutting threads, and did not use lead to connect together. I have brought this coil which I am telling you about to my house and run concentrated lye-water through it, and then run lime-water also, and yet it tastes.

Please inform me, if you can, what to do with this coil. The doctor wants this one cleaned. The ice sits in the coil, which forms a box when connected together; the water, after it is filtered, stands in the coil and gets cold, and they draw from the spigot at the bottom for table use.

A. If the water passing through the coil tastes " badly from oil," doubtless there is oil in it, which the treatment with lye-water has failed to remove. The treatment with the alkali should be very thorough, and every part of the inside of the pipe should come in contact with it. A gentle heat - say steam at low pressure - might destroy the oil without injury to the coil.

As the coils made by our correspondent give no trouble, there obviously is one remedy left in case the above fail - that is, to throw away the old coil and make a new one. These coils should be tin pipe.

Figure 64.