Researching various old texts for Little Book of Nits has thrown up some though-provoking comments from yesteryear.
1806: “It is affirmed by Leewenhoek that the male is furnished at the extremity of the abdomen with a sting; and that it is this instrument which causes the chief irritation suffered from these animals; the suction of the proboscis hardly seeming to have caused any perceptible pain on the skin on his hand.” Still, today, people confuse biting and stinging.
1806: “…there can be little doubt but that such cases, wherever they occur would be effectively removed by a proper application of mercury sublimate. Also called corrosive sublimate, mercuric chloride is thankfully no longer available for medical treatment, but people still think nothing of slapping poison on their own (and their children’s) heads.
1842: “The Head Louse is not like its congeners the companion of disease, or at least, ill health, produced from some temporary accident. On the contrary…it is well known, [the head louse] is common upon the most healthy children, as well as upon adults at particular periods, whose habits are not the least uncleanly.” It really is about time we bashed the squeamish idea of dirt and disease on the head.
1939: “Acetic acid or vinegar is still popular, owing to the belief that it loosens the cement attaching the egg to the hair. It has been known for years that this is not so, and that even after several days exposure…the cement is not dissolved.” In fact it has been known for over 100 years now that vinegar has no effect on nits. But it is still popularly touted as a solution.
1954 (after discussion of available insecticides): “DDT and BHC [benzene hexachloride] are slightly poisonous and, of course, should not be left in unlabelled jars or packets in the kitchen, where they might be mistaken for baking powder.” I suspect there is someone, somewhere in the world, promoting baking powder as a cure for head lice.
1954 (in the heady days of nylon and rayon appreciation): “No confidence should be placed in fabrics said to repel lice.” In fact, no confidence should be placed in anything said to repel lice.