Increased control by local authorities had finally put an end to poisonous adulteration.
"Beer adulteration had also practically ceased to exist by 1880, except for innocuous dilution. Fables continued to circulate, particularly at temperance meetings, about the poisonous ingredients allegedly used by brewers - a speaker in 1883 made the unsupported statement that 245,000 cwt of 'chemicals' were annually used in British breweries, and a few years later a book purporting to be a serious study of drinks and drinking habits stated that bitternesss in beer was produced by strychnine, absinthe, and nux vomica, and intoxication by belladonna, opium, henbane, and picric acid. In fact, cocculus indicus was last reported in 1864 and grains of paradise in 1878, and only rarely after this were old adulterations such as 'heading', capsicum, and liquorice discovered by public analysts as isolated curiosities. Narcotics disappeared from beer with the vigilance of local habits: by the closing decades of the century people no longer wanted to be stupefied and had turned away from porter and 'hard beer' towards lighter, less alcoholic varieties. Dilution remained the outstanding problem, and a seemingly intractable one: as late as 1900 one in five samples was watered, and a great many of these salted in order to restore lost flavour and, no doubt, increase thirst."
"Plenty and want: a social history of food in England from 1815 to the present day" by John Burnett, 3rd edition, 1989, pages 234 - 235.
Though stopping the watering of beer was more problematic:
"In many areas the newly appointed Public Analysts began to examine random samples and prosecute offfenders: in 1873 the PA for North Staffordshire found twenty-six out of eighty-nine random samples of beer adulterated, six with poisonous cocculus indicus. When the Inland Revenue Act 1880 restored the duty on beer, the Excise Department became more active in testing for adulteration by publicans, and in effect a concordat developed by which the Excise concentrated on dilution and the Public Analysts on other additions. . . the proportion of samples reported by Public Analysts as adulterated was comparatively small - 9.3 per cent in 1877 but falling quickly to between 2 per cent and 5 per cent up to 1914, though with occasional high variations (1892 16.8 per cent, 1900 8.8 per cent). The results of the Excise test for added water were very different, however - 78 per cent in 1880, 29 per cent in 1890 and still 15 per cent at the end of the century: the persistent rumours in late Victorian England that the workers' beer was watered had real foundation."
"Liquid pleasures: a social history of drinks in modern Britain", by John Burnett, published by
Routledge, 1999, ISBN 0415131812, page 123.
There you have it. Adulteration with poisons was a thing of the past by 1880. Watering survived much longer. At the risk of offending any publicans reading this, does watering still go on? Or is British beer already watery enough?