From Basil Walby

As a statistician, former editor of The Analyst, and now a grumpy old man, I was disappointed to see that RSC Publishing is promoting spurious precision in its advertisement in Chemistry World  (July 2006, p47).  

Impact factors are notoriously variable, making the quotation to three decimal places more than I can tolerate in a scientific publication. Surely 2.8 is more adequate in this instance? A L Bacharach would not have approved. 

B Walby CChem MRSC
Melbourne, Australia

Claire Derby, editor of The Analyst  replies:  

The impact factor quoted in the advert was the official 2004 value published by ISI. However I do appreciate the point that the number is not meaningful to three decimal places. Since July’s advert was published, I’m pleased to say that The Analyst’s  impact factor has risen yet again to 2.858 (or 2.9 if you prefer).


From Alex Brindle

I hate to be pessimistic about the degree I chose to do (graduating more than 11 years ago) but has anybody else noted the financial penalty for being a chemist? 

It is always interesting to see the jobs that often highly qualified chartered chemists can apply for and then compare the positions against other fields. For example, the July edition of Chemistry World  (p65) carried a job for a materials technologist to work with the London underground in some way. The job offers up to ?40,000, provided you have a degree, are chartered, have five years experience and preferably at a senior level. Or then again I could skip the four year degree, forget the five years of experience, and earn virtually the same as a tube driver. 

There are other interesting comparisons with similar degree subjects (I will not compare with law or finance as this always leads to unfair comparisons). Take chemical engineering as an example - similar amount of hard work at university, similarly demanding role. Well, if you think that, please take a look at the Institute of Chemical Engineers’ jobs section and note the salaries of the positions on offer. Most of them are well above the ?20,000 to ?35,000 typically seen in Chemistry World

Is it market forces and the chemist’s low value contribution that keep salaries low? I hope it isn’t but it is food for thought. 

A Brindle CChem MRSC 
Copenhagen, Denmark


From Alan Dronsfield

I was delighted to read that chemists are still pursuing ’chemicals that can harvest the energy of light, storing it and then releasing it on demand’ and that at last their efforts have been attended by success (Chemistry World, August 2006, p16).

The satirist Jonathan Swift raised this as a possibility as early as 1726. Writing in Gulliver’s Travelshe first describes the appearance of his chemist, goes on to outline the project and then makes a plea for more funds to continue the work. Much of this has a modern-day ring to it: 

The first Man I saw was of a meager Aspect, with sooty Hands and Face, his Hair and Beard long, ragged and singed in several Places. His Cloathes, Shirt, and Skin were all of the same Colour. He had been Eight Years upon a Project for extracting Sun-Beams out of Cucumbers, which were to be put into Vials hermetically sealed, and let out to warm the Air in raw inclement Summers. He told me he did not doubt in Eight Years more he should be able to supply the Governors Gardens with Sun-shine at a reasonable Rate; but he complained that his stock was low, and intreated me to give him something as an Encouragement to Ingenuity, especially since this had been a very dear Season for Cucumbers.  

A T Dronsfield CChem FRSC
Chairman RSC History Group


From Peter Urben

There has been intense media speculation about the chemistry of liquid explosives following news of a terrorist plot to blow up planes from the UK to the US.  

There is nothing new about liquid explosives: nitroglycerine is the second oldest explosive to have found mass use. Most of the liquid glycolic nitrate esters would do, but dynamite being almost obsolete, manufacture is now small and the product well guarded. Manufacture is not too hard, if you have concentrated sulfuric acid to hand (nitric you can make from that, even in situ). 

Methyl nitrate, the ester most often named by terror experts, would not do. It is much too volatile and consequently highly poisonous; I think these ’experts’ confuse it with nitromethane. 

Rumours spread from intelligence and security sources have named triacetone triperoxide (TATP). This is rather less liquid than TNT, nor does it need a detonator. In fact, it is almost certainly crystallisation of the solid that permits terrorists to make it.  

A variety of mixes of water-miscible organic solvents with higher grades of hydrogen peroxide would constitute very effective Sprengel explosives. However, high test peroxide is difficult to obtain in quantity, even for the chemical industry, because it is itself so hazardous that the makers insist on inspecting the facilities of those ordering. 

Nitromethane, usually considered to be a solvent or special fuel, is, in fact, an explosive comparable with TNT, and easily sensitised to become detonable without a booster. 

However, I distrust the whole story. A bottle can contain a block of material suitable for an explosive charge. However there can be little problem in disguising most of the commoner solid explosives as block confectionary, such as chocolate or Scottish tablet. 

Caution militates against publishing much more detailed comment. The available evidence may suggest that al-Qaida is chemically more intelligent than MI5, but, none the less, it should not be offered ideas it may not have had. 

P G Urben  
Editor, Bretherick’s handbook of reactive chemical hazards


From Mike Horner

I too would be grateful for an explanation for the blue lines that appeared after putting a plate repaired with Araldite in the dishwasher (see Chemistry World, August 2006, p32).

I repaired a hole in the dish washing machine cutlery tray with a plastic bag tie which was then smeared with Araldite. Within a very short number of dishwasher usages the Araldite turned a deep blue/green colour and remains very hard. 

M Horner CChem MRSC
Stonyhurst, UK


From Richard Skipper

As one who suffers from European mosquito bites, but strangely enough not from Asian ones, I was attracted to the work on making humans ’invisible’ to mosquitoes, albeit in Africa, in the August issue of Chemistry World  (p52). 

Indeed everything in the article was extremely positive, including the fact that the chemical mixture had odours that fellow humans would not detect. However, noting that the chemicals to be used were based on those derived from giraffes and water buck it did strike me that a human user of the deterent could incur the unwelcome attention of either, or both, of these animals.  

I await further developments with interest and hope they include the results of trials to determine the interaction, or otherwise, of human subjects and any passing buck. 

R Skipper CChem FRSC
Winchester, UK


From Paul Davies  

I would like to invite Chemistry World readers to assist with our research into the loss of hair and hair colour. 

In individuals with a genetic predisposition, testosterone and its more active metabolite 5-alpha-dihydrotestosterone can induce hair loss in the characteristic male or female pattern. Loss of hair pigmentation is also part of the ageing process. Melanocytes in the hair follicle synthesise melanins which are incorporated into developing hair shafts producing the final hair colour. But at the beginning of each hair growth cycle, some or all of the melanocytes are lost, resulting in greying or whitening of the hair.  

The chemistry of these processes is not precisely understood, and we are investigating whether men who go grey before the age of 30 do not subsequently proceed to full hair loss.  

Readers of any hair type (with or without loss) who are interested in assisting with this research should go to the website and follow the ’survey’ link to answer 10 short questions. 

P G Davies CChem FRSC
Esher UK


From Gerald Scott

In the editorial on plastic bags, the statement that biodegradable plastics that ’end up in landfill’ emit methane is a half-truth (Chemistry World, July 2006, p2). There are two types of biodegradable plastics. Hydro-biodegradable materials (eg starch based) do emit methane in the absence of oxygen but oxo-biodegradable materials (eg polyolefins) do not and once they have fragmented in the surface layers of landfill, they remain essentially unchanged. Both types of polymer can be readily composted. 

The Environment Agency, reported as being the source of the above misinformation, should be informed that polyethylene was originally manufactured from sugar (molasses) by the low-energy catalytic dehydration of ethanol. As the economics of the production of ethylene shifts from fossil fuels to abundant bio-resources, polyethylene will increasingly become a co-product of the biofuels industry and will return to its original status as a bio-based polymer. The Carrier Bag Consortium is thus correct, since biodegradable polyethylene bags may also be recycled with conventional polyethylene bags. 

G Scott CChem FRSC
North Yorkshire, UK


From Hamish Kidd

Many thanks to all our readers who offered their back issues of Chemistry in Britain  to our editorial office. Many attics were raided, and someone even offered mint copies still in their plastic wrappers! We now have a complete archive set. 

H Kidd
Chemistry World, RSC