Science
Laboratory sleuths
Bernard Dixon
Textiles imported into Britain have to be correctly declared for Customs purposes. During the second half of 1974, there was an influx of dolls and clothing sets for dolls. Samples of each were sent to the laboratory for analysis, which showed that over half of the sets had been wrongly declared.
Also last year, two statuettes were seized during an investigation into drug smuggling, one in America and the other in Britain. It was important to establish whether they had a common source of manufacture. Again, this was done by scientific tests, which revealed that both statuettes had an unusual but identical composition.
Chemical analysis also reassured the authorities that there was no danger from lead contamination in kettles made in the United Kingdom. A Canadian report had raised the -alarm about leaching of lead from soldered joints in kettles, but laboratory examination of British models showed them to be safe.
A fourth scientificstudy carried through last year pinpointed the cause of a nasty, varnish-like odour reported in the pre-cooked, canned rice being consumed increasingly by the Armed Services. Having identified the molecules responsible, chemists were able to suggest a modification to the cooking process, which should prevent unwanted smells from developing in future.
These four examples of scientific backroom work are taken at random from the 165-page Report of the Government Chemist 1974, which was published last week. They are typical of the conliderabIe" range of investigations pursued by the Laboratory of the Government Chemist on behalf of government departments. Portraying the varied and ever-changing nature of day-to-day technical expertise required by central government, this annual report also reflects' many different aspects of social change. For that reason, it is always fascinating reading.
The laboratory's involvement in questions of smoking and health is particularly interesting. It was the Government chemist's staff who devised the methods now employed to measure the tar and nicotine levels of cigarettes, which have been listed in the three 'league tables' published since they were initiated in April 1973. One consequence of this publicity has been that, of the ninety-four brands common to all three tables, a third have shown a significant reduction in tar yield. The sharp dividing line between filter and plain cigarettes has disappeared, due to consider-' able decreases in the amount of tar produced by many plain varieties. Manufacturers and smokers . alike have noted the figures and acted accordingly.
A related topic covered in the 1974 report — the detection of 'controlled drugs' — illustrates the sort of difficulties that arise when the law and the science necessary for its enforcement get out of joint. Thus forensic scientists are not happy that the longstanding legal description, 'flowering or fruiting tops of cannabis', Was replaced in the Misuse of Drugs Act 1971 by 'any plant of the genus Cannabis'. Practical difficulties stemming from this include the identification of finely-chopped leaf as cannabis — and indeed the classification of hemp seed (intended for birds). The Government Chemist's report points out the dilemmas of scientists involved in analysing such materials, particularly when there have been conflicting decisions, about them in both the divisional and magistrate's courts.
Another, some would say appalling, sign of the times is the gradual replacement of genuine meat by "texturised vegetable protein' in packeted, canned and frozen foods. Instead of succulent lumps of authentic meat, soya bean, for example, is processed and done up to resemble beef. As with butter, we are all convinced that we can tell the difference. Distinguishing between the two scientifically and absolutely is much more diffi,cult. But UM Government Chemist has been equal to the task. The first successful prosecution of a manufacturer for misleading labelling (of "Limmits beef flavour casserole" and other dried meals based solely on vegetable protein) occurred recently, at the end of June.
Among other backroom achievements documented in this year's report: ensuring that sheep-dip insecticides do not find their way into mutton in dangerous concentrations; analysing handwriting as a means of uncovering tax evasion by building industry workers on 'the lump'; and checking that a new mould-release agent used in making glass-fibre containers did not affect adversely inflatable liferafts.
Scientists, it seems, still have their uses — whatever our station in life.
Dr Bernard Dixon is editor of New Scientist
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