From Edward Johnson
From Edward Johnson
I regret to say that Katie Gibb’s article, Uncorking wine’s characteristics, added little to my understanding of wine chemistry (Chemistry World, December 2005, p39). I have been trying to get to the bottom of some wine issues for years. About eight years ago, I spoke to someone at the Wine Society and we had some pleasant exchanges without making matters any clearer.
My main problems are with corks and 2,4,6-trichloroanisole (TCA). I would be quite interested to know about the microorganism that is resistant to trichlorophenol and can metabolise it, and much more interested in the origin of the trichlorophenol (while I’m being pernickety, there are large numbers of chlorobromophenols that may be involved if tribromoanisole is a possibility).
Next, there is a statement about plastic stoppers being more likely to permit oxygen ingress because they don’t fit as closely as natural cork, yet the metal screw cap is better, in spite of its reliance on a plastic-glass seal 2-3mm long compared with ten times that distance for the plastic stopper. In any case, how much oxygen is required to spoil a bottle of wine? A recent leaflet from the Wine Society made the same statements, and I protested at the time. It would be nice to see details of some proper research results complete with figures.
E Johnson MRSC
From Paul O’Brien
In discussing the formation of the new school of chemistry in the University of Manchester (Chemistry World, December 2005, p36), Bea Perks and Katharine Sanderson referred to the closure of the Umist chemistry department.
The new university was formed by the complete dissolution of both the Victoria University of Manchester and Umist to form the new institution. In the same way the chemistry school is a new one; in one sense two departments closed. However, the new school has led to an expansion of chemistry in Manchester with several new appointments having been made.
A capital investment exceeding ?14 million has been made for a new building to allow collocation of members of the school, which is scheduled to be completed later in 2006. The school will also actively engage with a number of the university’s new research institutes, most notably: the Dalton Institute for Nuclear Science and Engineering, the Manchester Interdisciplinary Biocentre, and the Photon Science Centre.
Chemistry is expanding in Manchester: no closures here.
P O’Brien CChem MRSC
Head of school of chemistry, University of Manchester, UK
From Les Ebdon
Governments have a duty to protect their citizens and modern techniques of urban terrorism create new threats to which democratic governments must respond. In the UK the tragic effects of the explosions in London on 7 July 2005 have focused attention on this issue. The UK Government has proposed new legislation in the form of a terrorism bill.
Initially much parliamentary debate centred on the time for which terrorist suspects could be held for questioning before being charged. Various groups were, however, highly concerned that some of their legitimate activities might fall foul of any new law.
Chemists and librarians were particularly concerned that rapidly drafted clauses about it being an offence to make a ’noxious substance’ or to train or teach somebody to make such a substance could be said to make whole areas of chemistry illegal. Librarians were concerned that merely loaning out a first year chemistry text book with a method for preparing a chemical which could be used as an explosive would result in a lengthy prison term.
It is in such circumstances that the lobbying power of organisations such as the RSC and Universities UK (UUK) are invaluable. As an RSC Council member and a member of UUK, I was in a grandstand position to see how it is possible to ensure, in the more measured debates of the House of Lords, that safeguards are inserted into legislation.
As a consequence of RSC intervention, chemistry teachers can continue to engage in ethical scientific teaching and research without fear of unintended consequences. The onus will not be on university lecturers or librarians to be sure that their students are positively vetted.
The key test will be one of intent and no professional chemist would want to see their teaching, research or publications used to create the kind of indiscriminate carnage seen in London last July.
L Ebdon CChem FRSC
Vice chancellor and chief executive, University of Luton, UK
From Edward Behrman
Emma Davies reports that Sanger used the dideoxy technique to determine the sequence of
X174 DNA (Chemistry World, December 2005, p48). Sanger actually used an earlier technique, the plus-minus method. This is well-discussed by J Hindley in DNA sequencing, 1983, Elsevier.
E Behrman MRSC
Ohio State University, USA
From Joseph Bunnett
Graham Hills said that chemistry. should only enter the [university] scene at the level of the graduate school (Chemistry World, December 2005, p26). This view fails to acknowledge that chemical thought and practices are fundamental to many disciplines and professions, including not only chemistry, but also biology, medicine, pharmacy, food preparation, engineering, creative art, agriculture, pest control, environmental science, water supply, and sewage disposal.
The role of chemistry is rather like that of mathematics; just as mathematical thought and calculations are fundamental to many areas of human activity, so also are practices based on chemical understanding. And just as mathematical thought and calculations are taught in schools and in universities at elementary levels, so also should chemistry and its practical relevance.
J Bunnett MRSC
University of California, Santa Cruz, USA
From John Davies
At a time when the teaching of chemistry seems under threat, schools are rearranging staffing to introduce teaching and learning responsibility (TLR) payments.
As head of science and chemistry in a large comprehensive, I am alarmed that our school is to abolish all heads of department. The science department is to be combined with CDT and child development and the new faculty will have only three of the new TLR posts, only one of which is likely to be held by a scientist. I retire the day my post disappears, but my colleagues and I are all concerned that the changes will have a drastic effect on the teaching of science and damage our successful science sixth form which has produced many good scientists.
Any career progression for younger staff will not be via subject teaching. I fear that our school will not be alone in doing this. Alarm bells should be ringing.
J Davies CChem MRSC
From P G Urben
I have just bought some cheap washing powder and the label tells me that it contains oxygen-based bleach (anglice, a peroxide), as do its more expensive rivals. The white paste used to harden the filler with which I am restoring my window frames is benzoyl peroxide. I have just seen some adverts for ear drops, which tell me they are based on urea peroxide. Though past the years for acne - treated with peroxides - I have no dentures, but if I had I would clean them with a peroxide.
Peroxides are widespread and almost all will test positive as explosives in any test which relies on acidic hydrolysis to hydrogen peroxide - so a bit less hype (eg Chemistry World, December 2005, p50) please.
Even should you develop a specific test for 3,3,6,6,9,9-Hexamethyl-1,2,4,5,7,8-hexaoxacyclononane (TATP); it is the product of an acid-catalysed reaction between hair bleach and nail varnish remover. Would that scarce animal, the thinking chemist, be vastly surprised to find traces in environments inhabited by young women, on the hands of the ladies themselves; or even on those of young men?
Mancini’s account of the explosion mechanism of TATP is gravely defective. Entropically favoured though the process is, you need work (ie heat) to tear a bus apart.
I do not have enthalpy of explosion on file for TATP, but it cannot be much less than 2.5 kJ/g. Moreover, show me a site where oxygen and carbon dioxide cannot be detected.These are demonstrable products in a bomb calorimeter, but not at explosion sites; in fact oxygen levels at the latter will surely be depleted.
It remains paradoxically true that the first requirement of any explosive, even as unsafe a one as TATP, is that it be stable. More exactly, that it be metastable enough to isolate and store. At the theorist’s level this means that the initial step of the sequence of decomposition reactions must be endothermic - ie there is an activation energy. Only in this sense is an explosive non-enthalpic and all explosives show it.
P G Urben
Editor, Bretherick’s handbook of reactive chemical hazards, Kenilworth, UK
From Peter Nelson
Graham Hills thinks that we need no chemistry departments of the existing kind (Chemistry World, December 2005, p26). He thinks that undergraduates would be better spending their time and energy ’acquiring the generic skills of the intellect and technology’. This presumably means that he would like them to take a general degree in science and technology.
I agree with him that science undergraduates should receive a general education in science and technology, but I believe that the chemical part of this should accurately reflect the distinctive character of chemistry as a science, and that students should be allowed to specialise in chemistry before they graduate.
Chemistry is a very broad subject, and while physical and theoretical chemistry are much like physics, inorganic and organic chemistry are not. They are guided by only very approximate general principles, and proficiency in them requires a good factual knowledge of chemical behaviour.
To teach them, chemistry departments of the existing kind are, I submit, needed.
To justify this role, however, departments, along with schools, need to mark Hill’s criticism that they have become too specialised. This trend needs to be reversed.
P G Nelson MRSC
University of Hull, UK
From Matthew Godwin
We are conducting an academic study into the brain drain of the 1950s and 1960s. To assist us in our research we are now seeking people who could share their recollection of the brain drain, either as emigrants themselves, or as those who seriously contemplated emigration. If there are any readers who fall into these categories then we would be very pleased to hear from them.
Department of Science & Technology Studies, University College London, email: email@example.com
From Michael Baldwin
I regret that the formula for gunpowder combustion (Chemistry World, January 2006, p26) contains an error, which was entirely down to me.
The correct formula is:-
14KNO3 + 4S +12C =4K2SO4 +3K2CO3 +8CO2 + CO +7N2
M Baldwin CChem FRSC
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