From Clifford Jones

In the UK, batches of faulty petrol were recently found to have been contaminated with silicon (see p11). Burning this fuel would have formed silica (SiO2) particles which clogged the oxygen sensor at the exhaust, causing it to fail in its role in ’engine management’.  

A simple laboratory demonstration of this effect is in fact possible. Take a methylated spirit burner with a wick and to the ethanol fuel it requires, add 5 to 10 per cent of a silicone oil. Place the burner in a fume cupboard, light the wick and wait a few minutes to observe white particles of silica exiting the flame. This is an established method of coating a thermocouple bead with silica to prevent it from having a catalytic effect, and it also enables what is believed to have happened to the cars using contaminated petrol to be demonstrated very easily. 

A silicone oil content of 5 to 10 per cent is suitable for the thermocouple coating application referred to and for any pedagogic application of the method. It is not of course being suggested that silicon compounds in the contaminated petrol were present in concentrations as high as that. 

J C Jones FRSC
University of Aberdeen, UK 


From Clive Delmonte

It is tempting to sympathise uncritically with Ian Whitfield’s desire to return to the ’scientific method’ and to move away from belief and, of course, he is right to complain about all the examples he cites (Chemistry World, March 2007, p36). There are problems however. 

Sir Karl Popper demonstrated that, in many situations, propositions in the natural sciences could never be proved, only disproved, and his work on the meaning of empirical truth in science was further developed by van Fraassen in The Scientific Image, and by others. 

Oh, how I pine for those happy, sunlit days of my innocent youth, when I could just buzz about ’proving’ things. 

C Delmonte CChem FRSC
Norfolk, UK


From Richard Jones

What a sad letter from Ian Whitfield (Chemistry World, March 2007, p36). His bonnet appears to have a bee in it (climate change), but why use as the peg on which to hang it a broad condemnation of modern science? 

He objects to the phrase ’scientists believe that . . .’ as the antithesis of scientific method, but most of science is and always has been constructed on belief, although a belief that is very different from religious belief. Belief in the scientific sense is utterly dependent on scientific method: research I carried out with my own hands and my own brain required a belief that the squiggles coming out of an NMR spectrometer were related to the structure of a molecule in ways that previous scientists had proposed.  

When the science is a little further removed from our own experience we take almost all of it on trust, on the basis that it has been developed by applying scientific method. To take but one example of the thousands in which my ignorance exceeds my knowledge, I’ve never seen a nanotube - I don’t think the word had been coined while I was still a practising chemist - nor have I read a single original paper about them. Does that mean I should assume they don’t exist? Am I just being fooled because I’ve been told about them three times? (Bellman’s philosophy, by the way, not Humpty Dumpty’s) 

Good science and bad science have always been with us, as have good and bad scientists. But the best of modern science, aided by computers and other modern technology, is better than ever, addressing issues that were beyond its reach only a few years ago. And some of the very best of modern scientists are working in the area of climate change and global warming. I know one or two of them: they are much better scientists than I ever was - and I believe them. 

R A Y Jones FRSC
Peeblesshire, UK


From George Seaborn

With reference to the article entitled Living on credits  (Chemistry World, February 2007, p40), all that reducing the carbon dioxide emissions in the UK would do would be to leave more fossil fuel to be burnt by other countries, particularly China, India and the US. 

Oil companies can sell all the oil they produce. China is hungry for oil. So if we in the UK burn less oil there will simply be more oil for China to burn. The result will be that world carbon dioxide emissions will be unchanged. 

The only way to reduce world carbon dioxide emissions from energy production is to restrict the world production of fossil fuels. The result will be that prices of fossil fuels will increase but that will provide an incentive to use energy more efficiently, to produce more energy from other sources, and to produce that energy more efficiently.  

However, before restricting production of fossil fuels, world carbon dioxide emissions could be cut by putting out the enormous fires that are burning in coal seams in China (China says it cannot afford to put them out but it can afford to support an enormous army, to make nuclear weapons and to have an expensive space programme) and to stop destruction of tropical rainforests in Indonesia.  

Stabilising the world population would no doubt help too. The world population cannot increase indefinitely without limit and now is as good a time as any to start to control it. 

G S Seaborn CChem MRSC
Banstead, UK


From Albert Moulder

Many ideas have been postulated on how to reduce CO2 emissions. Through Chemistry World’s wide readership, does someone know how much human beings produce just by breathing? With every breath we exhale CO2. Does the amount exhaled relate to factors such as our age, amount of exercise, or the amount or type of food we eat? Does the world now contain so many people that we are slowly killing it off?  

A Moulder
By email


From Ed Walker

Many of us watched Channel 4’s The great global warming scandal, screened in the UK in March, with fascination because it appeared to debunk completely the perceived wisdom that the current increase in global warming is anthropogenic. It suggested that the correlation between carbon dioxide and warming in ancient ice cores was a consequence of warming and not vice-versa. It also suggested that global warming was due to increased radiation from the sun, perhaps a more rational idea than that of blaming carbon dioxide, which apparently is not a very efficient greenhouse gas. 

We obviously need to reduce our use of fossil fuels because these will eventually run out and we need time to develop more sustainable, long-term sources of energy, but to be asked to do so on this false premise is creating a great amount of pseudo-science as a result of political pressure. 

E Walker CChem MRSC
Bexhill on Sea, UK


From Colin Cook

One possible approach to solving the problem of how to mix two different liquids at the microscale might be to put a ’zebra crossing’ pattern of different coatings on the wall of the channel (Chemistry World, December 2006, p44). Each fluid will have a different wetting angle on each coating, which means that a motion at right angles to the channel wall will be set up as each fluid crosses the pattern. This should result in mixing of the fluids. 

C Cook CChem MRSC
Basildon, UK


From John Wand

Thank you for an interesting article on the Titan microscope at the London Centre for Nanotechnology (LCN) (Chemistry World, December 2006, p14). I was disappointed, however, to see no reference to the funding for this instrument, which came from the Engineering and Physical Sciences Research Council (EPSRC) through its responsive mode line. This was particularly disappointing because a senior academic from University College London, UK, took me to task at the opening of the LCN because ’EPSRC never supports equipment’.  

J Wand
Materials programme manager


From William Butler

I am writing to inform you that, after many years, the science department at Mid Kent College of Higher and Further Education, UK, has reinstated an HE course in chemistry.  

The course has been in operation since September 2006, and is run by experienced members of staff who have both industrial and teaching experience. 

As a member of the RSC, I feel it important that reinstating the course should be highlighted as a positive thing for chemistry in light of courses being cut. It is important to encourage students to look at chemistry as a career. 

We would therefore welcome comments from Chemistry World readers about our efforts to re-establish a level of education that was successful in the past and which has been absent for at least 7-10 years from the curriculum at Mid Kent College. 

W Butler CChem MRSC
Gillingham, UK


From Khalid Maqbool Siddiqui 

It has always been a mystery to me; whenever I read Chemistry World  I find that Indians and Chinese are progressing non-stop in chemical sciences while Pakistan, being their closest neighbour, is lagging behind in this regard. So, I decided to conduct a survey to find out what the problem was and I found out that many people, although interested in chemical science, are simply afraid that if they opt for chemistry for instance, their career might be destroyed owing to the infrastructure in Pakistan for chemical students. 

This explains why organisations such as the RSC can play a pivotal role in different countries for the betterment of chemistry. We hail heartedly what the RSC has done so far. 

K M Siddiqui AMRSC