Having been so frequently benefited by the instruction, especially photographic, issuing from your most useful periodical, I feel myself almost bound to contribute my mite of information whenever I may chance to have the power of doing so; consequently, should you not get a better method of assisting MR. F. M. MIDDLETON out of his difficulty of softening old paint, as describe in the "N. & Q.," No. 191., I beg to offer him the following, and from experience I can vouch for its certainty of leading him to the desired result. Some years since, having had occasion to enter a lumber-room of an old building, I was struck with the antiquated appearance of an arm-chair, which had, in days long gone by, been daubed over with a dirty bluish paint. Finding, on inquiry, that its owner set no particular value on it, I met with but little difficulty in inducing him to make an exchange with me for a good mahogany one. Soon after its being brought into my house, one of my domestics discovered that it positively swarmed with a species of lice, issuing from innumerable minute worm-holes and crevices, which of course rendered it in its present state worse than useless. Determined not to be deprived of my prize, I resolved on attempting to rid it of this troublesome pest by washing it over with a strong solution of caustic soda, made by mixing some quick-lime with a very strong solution of the common washing soda (impure carbonate of soda), and pouring off the clear supernatant liquid for use. This proceeding, much to my satisfaction, not only succeeded in entirely getting rid of the vermin, but on my servant's scrubbing the chair with a hard brush and hot soap and water, I found that the caustic soda had formed a kind of soap, by chemically uniting with the oil contained in the old paint, thereby reducing it to such a state of softness, that by a few vigorous applications and soakings of the above-named solution, and subsequent scrubbings, my new favourite was also freed from its ugly time-worn jacket of dirty paint, discovering underneath a beautifully carved and darkly coloured oaken surface. After being perfectly dried and saturated with linseed oil, it was frequently well rubbed, and the {59} chair stands to this day, like some of the valuable discoveries made by the alchemists when in search of the Elixir Vitae, or the Philosopher's Stone, an example of a fortunate and unexpected disclosure made when not directly in search of it. I have since learnt that a fluid possessing the above-named detergent qualities, is to be purchased at some of the oil and colour shops, the formula for its preparation being kept a secret. HENRY HERBERT HELE. Ashburton, Devonshire. P. S.--In making the solution on a caustic alkali, perhaps I should have said that the common carbonate of potass of commerce will do as well as the common carbonate of soda, if not better, from the probability of its making a stronger solution.