100 YEARS AGO

For some time past there has been a large and apparently influential party of alarmists with regard to the use of preservatives [in food]. These have all been heard in length by the Committee which has just reported. Their evidence consisted for the most part of elaborate a priori argument, in support of which the most profound erudition was occasionally produced; but, as the report politely says, the opinion expressed was not always based directly on fact. In fact, if an inquirer turns the 500 pages of the Blue-book over in search of unequivocal instances of injury to health from preservatives or, indeed, colouring matters in food he will be lucky if he finds a single one... Upon such data it is obvious that the prohibition of preservatives en masse was out of the question, and the recommendations of the Committee practically resolve themselves into the regulation and control rather than the prohibition of preservatives. There are, however, two exceptions to this; formaline or formic aldehyde is prohibited altogether, and all preservatives and colouring matters are prohibited in milk.

From Nature 5 December 1901.

50 YEARS AGO

It has been suggested by Kistiakovsky that the mechanism of smell could be explained by the existence in the olfactory mucosa of four enzyme groups... and that odoriferous substances are distinguished by their differential inhibition of particular enzyme groups. The same explanation might be used to account for a mechanism capable of distinguishing between substances of different taste... we suggest the following tentative hypothesis to explain [the enzymes'] relation to the mechanism of taste. The chemical reaction involved in the breakdown of substrate by enzyme presumably gives rise to ionic changes which would induce currents in nearby nerve fibres... A tasting substance coming into contact with superficial enzyme sites... would inhibit the activity of an enzyme in one site, accelerate the activity of an enzyme in another site and have no effect on enzymes in other sites and so on. It would therefore alter the pattern of nerve impulses reaching the brain, and each substance would produce its own individual pattern. Since there are six main sites of enzyme activity... we have a mechanism for distinguishing between 2,160 tasting substances.

From Nature 8 December 1951.