Tar water

An authentick narrative of the success of tar-water, in curing a great number and variety of distempers: with remarks and occasional papers relative to the subject: to which are subjoined, two letters from the author of Siris, shewing the medicinal properties of tar-water, and the best manner of making it. Tar water was a quack remedy popular in the medieval period, consisting of pine tar and water. By all accounts it was foul-tasting and of course entirely ineffective, so it died out, but enjoyed a brief resurgence in the 18th and 19th centuries.

History
It was heavily promoted by the Irish philosopher and clergyman Bishop George Berkeley, notably in his book Siris (1744). At a time when Ireland was in dire straits, its inhabitants in typically desperate poverty that were exacerbated by the harsh winter of 1739-40 and almost no physicians to be found outside Dublin, Berkeley seemed to offer a cure for all Ireland's ailments. He claimed he had tried it out on various friends and neighbors and cured many cases of fevers and other diseases (although this would not pass the modern standards of clinical trials), mixing this with mystical ideas about how flowing tar water mimicked the forces of natural harmony which could flow through and unite all people, in Ireland and elsewhere. His contemporary prominent doctor Thomas Reeve (later president of the Royal College of Physicians) claimed Berkeley had merely alighted on the cheapest substance he could find and would be as well promoting water without the tar, which was even cheaper and more widely available. But tar water was probably less harmful than contemporary alternatives such as Thomas Dover’s Mercury Powders and easier to obtain than Dr. Arbuthnot's ass's milk diet. Berkeley's book went through six editions from 1744 to 1748 (the first edition called A Chain of Philosophical Reflexions and Inquiries concerning the Virtues of Tar-Water and divers other Subjects connected together and arising one from another, the second with the better-known title Siris, from seira meaning chain); it was translated into several European languages and seemed to kick off a craze for tar water across Europe.

It is mentioned in Charles Dickens' Great Expectations: young Pip and his brother-in-law Joe were often force-fed it by Mrs. Joe.

Today
The tar aroma is popular in Finland and is available as an aqueous solution. It is used in candies, liqueurs, soaps, and shampoos. This kind of tar water isn't usually associated with health claims. However, tar shampoo is advertised as being effective for dandruff.