Science and the Criminal

by C. Ainsworth Mitchell

The presence of traces of arsenic in food products is a very much more serious matter than the presence of a small amount of copper.

Arsenic is undoubtedly a cumulative poison, and the effects produced by the long-continued repetition of small doses were shown by the numerous fatal cases of poisoning caused by drinking arsenical beer, in the poisoning epidemic a few years ago.

It may be safely asserted that for twenty years before that outbreak it had never occurred to anyone to test beer for arsenic. The possibility of its being present ought to have suggested itself, but apparently it never did.

The origin of the arsenic in the beer is obvious, when it is remembered that glucose is one of the substances commonly used in the brewing of beer, and that glucose is prepared by treating starch with sulphuric acid, which, is in turn, frequently made from iron pyrites containing arsenic.

After the source of the arsenic in the Manchester beer had been discovered, an arsenic “scare” set in. Every possible description of food was examined, and traces of arsenic were found in many hitherto unsuspected places.

Malt, dried in kilns and allowed to come in contact with the fumes from coal, invariably contains an appreciable amount of arsenic derived from the coal, and even malts prepared with the greatest care usually contain about one part per million of arsenic. For all practical purposes, however, so small a trace is negligible.

The members of the Royal Commission which was appointed to examine and report on arsenic in food were strongly divided with regard to whether any trace of arsenic should be permitted in food. Some were in favour of absolute prohibition, while others recognised that, even if this were done, the rule could never be rigidly enforced. Hence their report bears evidence of a compromise, for it states that although the Commission had been unable to discover that such minute traces of arsenic were injurious, yet they were unwilling to admit that any quantity, however small, was permissible in food.

Subsequently they recommended that a particular test should be used which would ensure that arsenic in food and drugs should not exceed an infinitesimal trace, and that frequent tests of raw and finished materials should be made.

These recommendations are now widely adopted, and it is highly improbable that another epidemic of arsenic poisoning will ever occur again in this country.

No better illustration of the vicious circles in which adulteration may move can be found than in the practice of certain manufacturers of jam of the cheaper kind. Apple pulp is a common constituent of jams which conceal their identity under another name. Now, in the case of raspberry jam, for example, it is necessary to have the seeds as well as fruit pulp, and these seeds may be bought very cheaply from the makers of fruit essences.