From Graham Hills

How many chemistry departments do we need? How long is a piece of string? If you ask a simplistic question you must expect a simplistic answer. All that your correspondents are able to offer are patched-up versions of the status quo (Chemistry World, October 2005, p11).

More lateral thinking would suggest that the current arrangements are not just inefficient, they are fundamentally flawed and therefore doomed. While chemistry remains a vital strand of the scientific knowledge base it is not mainstream and, except in British secondary schools, never was. Moreover, by making it ever more specialised, ever more rigorous and ever more difficult, it has been steadily driven to the periphery of the envelope of the core knowledge we all need to know.

On the other hand, science and scientific thinking are mainstream and always will be. In its totality and general language, science needs to be understood by every civilised person for the good or evil it can do. Chemistry is a subset of science on a par with physics, biology, geology, computer science and the social sciences. Together they offer an Aladdin’s cave of amazing achievements of the human intellect. Even at a superficial level that basic science is more than enough for 99 per cent of the population.

Like law, medicine and engineering, in most countries, chemistry as a serious professional subject should only enter the scene at the level of the graduate school, the prime purpose of which should be to acquire and practise the skills of chemical research. Only the market will then tell us how many such research centres we shall need. 

How many chemistry departments of the existing kind do we need? The answer is self-evidently none. As undergraduates our time and energy would be better spent acquiring the generic skills of the intellect and technology. As a result we should all be better citizens and, incidentally, better research students.

G Hills  CChem FRSC
Professor emeritus of chemistry and former vice chancellor of the University of Strathclyde, Glasgow, UK


From David Thomas

I am puzzled over three claims about prions reported in Dennis Rouvray’s article (Chemistry World, October 2005, p30). First, that their infectivity is unaffected by boiling caustic soda; second, that they exist as solely proteinaceous particles; and third, that the individual molecules are linear peptides. 

A resolution of this inconsistency in the basic information strikes me as a more important task than delving into ever more detailed molecular biology. The idea of a peptide weighing about 20kDa, or a cluster of them, passing through the gut wall is also rather surprising.

One might also quite legitimately ask the question ’why bother?’. Rouvray himself quotes an infection rate of one in a million. The massive delayed epidemic, feared in the 1980s, is now impossible given any statistical distribution curve with a single maximum. Bear in mind that the people of that time’s mean remaining life expectancy was 40 years or, putting it more bluntly, a quarter of them have by now died from something else.

Unless research in this area is expected to give insight into other neurodegenerative diseases, resources might be better directed elsewhere. 

D W Thomas CChem MRSC
Haverhill, UK


From Brian Innes   

Sally Anderson’s letter, and the review of Penicillin man (Chemistry World, October 2005, p27, p55) rightly point out that the isolation of penicillin was due more to the work of Howard Florey, Ernst Chain and Norman Heatley than to Fleming. 

However, nobody appears to have recognised the contribution of the unsung heroes of Kemball, Bishop and Co, a small chemical firm in the East End of London (later bought by Pfizer).

My first job, as a research biochemist in fermentation products, was with this company in rather decrepit premises in Three Mill Lane, Bromley-by-Bow. There I heard tales of how employees had stuck at their posts throughout the Blitz, while fires raged around. They dispatched milk churns of raw brew by night train for further development by workers in Oxford.

I joined the company in November 1949, so I can no more than guess at the process on the basis of my own experience, although I well remember the aluminium churns in question. The fermenters were made from stainless steel, sterilised with high pressure steam from the factory supply, and held 50 litres of nutrient broth, seeded with Penicillium culture. Electric-driven paddles kept the broth in motion, while controlled filtered air was bubbled through. Undue frothing of the brew was reduced by slow drips of - in my own work - com oil.

The leader of the team in London was L Mackenzie Miall (also author, with his father, of one of the current dictionaries of organic compounds). His co-workers included John Ward and John Barnes. It is almost too late in the day, I realise, to salute their dedication and I can appreciate the disappointment they felt when the first licences for manufacturing the antibiotic were granted solely to Distillers of Speke.

B Innes MRSC
Montgaillard, France


From David Goodall 

I don’t know whether the ’Land heritage’ card was intentionally included with the November issue of Chemistry World or whether it arrived there by mistake. If the former, I must express my profound displeasure. A bill is currently proceeding through parliament to outlaw practices such as Land Heritage’s, and has the support of MPs of all parties and various organisations. 

The scam operates whereby land bankers buy green belt land, draw up plans for housing estates on the protected sites, and then sell them on at grossly inflated prices. Such development plans are designed to fool spectators into believing that a housing development is about to receive planning permission. The new landowners then, realising they have been duped, put pressure on local authorities to allow building. Green belt sites worth ?115 are being sold for ?18 000. Such practices threaten the green belt and put enormous pressure on already hard-pressed local planning authorities.  

May I suggest that the good reputation of my professional organisation is not tarnished by association with highly disreputable practices.  

D C Goodall MRSC  
Otley, UK  


From Norman Nicolson

The article on gunpowder and its effects is very good (Chemistry World, November 2005, p50). 

I know that gunpowder is made from potassium nitrate, sulfur and charcoal as stated, but the article gives the byproducts as CO2, N2 and potassium carbonate. What happens to the sulfur and what does it become? The article describes it as a fuel, so it must have burned. I also know that Chile saltpetre [sodium nitrate] was unsuitable for making gunpowder because it was deliquescent, but was there ever a process to convert it into potassium nitrate?

N D Nicolson CChem MRSC
By email


From Richard Brown

Eric Wolff (Chemistry World, November 2005, p32) makes a valuable point about mankind’s contribution to increases in the CO2 concentration in the atmosphere. However the ’units’ used to describe the CO2 concentration - ppmv - should be strictly avoided.

Parts per million (ppm), parts per billion (ppb), and other similar descriptors, simply represent multiples (10-6 and 10-9 respectively) of dimensionless quantities (or quantities with the unit ’one’) and are not units themselves. They are not part of the SI system of units and the International Organisation for Standardisation recommends that these descriptors should never be used. 

Unfortunately their use is so widespread that they have become tacitly accepted. To avoid ambiguity, any use of these descriptors must always include a clear description of the quantity they are intended to describe, ie mass fraction, amount (mole) fraction, volume fraction. It is still preferable to state that the mass fraction w = 2.3 X 10-6 rather than the mass fraction w = 2.3 ppm. 

However, the addition of extra labels to ppm and similar descriptors, such as in the case of ppmv (parts per million by volume) should be strictly avoided at all times. Ppm and similar descriptors should never be used in combination with other units. Since all concentrations are expressed per volume, ppmv is ambiguous. It could refer to a mass concentration, amount concentration, number concentration or a volume fraction, multiplied by 10-6.  

I suspect that the atmospheric chemistry community uses ppmv to represent a volume fraction. It has a known meaning within that community and has therefore become commonplace. This is a dangerous practice.  

When any scientific group needs to communicate with the wider scientific fraternity, failure to use accepted and unambiguous terminology can only cause confusion and potential error.  

R J C Brown MRSC  
National Physical Laboratory, 
Teddington, UK 


From David Silvester

Katherine Sanderson’s article about the birth of GE Healthcare was an interesting one (Chemistry World, October 2005, p48), but I was disappointed to see no acknowledgement given to the crucial part played by the Medical Research Council (MRC) in its conception.

In June, some of us celebrated the 50th anniversary of the inauguration, in 1955 at Hammersmith Hospital, of the world’s first medical cyclotron. This machine, designed, built and operated by the MRC’s team of engineers, physicists and chemists, produced the very short-lived, positron-emitting radionuclides that were used to test first the feasibility and then the extraordinary potential of positron-emission tomography (PET) in medical research and diagnosis. 

The MRC also funded and operated at Hammersmith the first PET-scanner in the UK in 1979, and for more than 20 years the MRC cyclotron unit, as it was known, was at the forefront of research into developing new radiopharmaceuticals for PET studies.

In 2001, the MRC entered into partnership with Amersham, and the cyclotron unit became Imaging Research Solutions (later Hammersmith Imanet). Then in 2004, as we read in the Chemistry World article, Amersham was purchased by GE Healthcare. Sadly, the future for continuing radiopharmaceutical research at Hammersmith now seems unclear.

D J Silvester CChem FRSC
Southport, UK


From Tony Whitehead 

In September Chemistry World  published a feature on Einstein (p38). Here at McGill University, Canada, we have pumpkin carving competitions at Halloween. Our research team entered ’Einstein 100’!

M A Whitehead CChem FRSC
Quebec, Canada