Lowe praise
From John Archibald
As a medicinal chemist who retired long ago, the first thing I read each month in Chemistry World, with eager anticipation, is Derek Lowe’s column – In the pipeline.
What a shame though, if this is only or mainly read by medicinal chemists. There is so much wisdom here every month that deserves a wide readership. It seems invidious to single out any one piece, but ‘Chemical space is big. Really big.’ struck me as a particular gem. His recent piece ‘Messy megamergers’ is another.
Notwithstanding Clive Delmonte’s criticism of Lowe’s writing, my suggestion to all who are not medicinal chemists is do read him anyway.
J L Archibald CChem FRSC
Devon, UK
Biblical names
From Stephen Cohen
While reading the article ‘Pepping up antibiotics’, I was surprised by Andy Extance’s reference to the ‘Old Testament’. Rather than using a Christian-based term for that series of writings, most scholars use the more-neutral ‘Hebrew Bible’, or ‘Torah’.
The Royal Society of Chemistry is an international organisation for all chemists, many of whom are not Christian. Terminology that doesn’t presuppose the rightness of a particular theology (that which supposedly supplants the so-called ‘Old Testament’ by a ‘new’ one), acknowledges the diversity of our organisation in terms of faiths (and even those without faith).
S M Cohen MRSC
New Jersey, US
Whither Foscan?
From Charles Stewart
Foscan was one of the most promising anticancer drugs to emerge in the 21st century. A photosensitiser, it is activated in situ with 652nm laser light directed at the tumour. It has significant advantages over other photosensiters and high sales were once expected. However, Scotia Pharmaceuticals, which developed the drug, went into administration in 2001 amid much acrimony and finger pointing. Shortly afterwards, Foscan was acquired by Biolitech, a diode laser company based in Jena, Germany, but sales flatlined at around 200 units of treatment per annum since then.
The lacklustre performance may in part be explained by corporate diversion with a long running patent dispute with US laser company AngioDynamics. This eventually resulted in a court fine of $74.9 million (£36.1 million) against Biolitech in March 2014 by the US district court of Massachusetts and the judge calling Biolitech’s conduct grossly contumacious. The case does not appear to have closed.
Patients may be the eventual winners though as Foscan has recently come off patent and generic companies are lining up with much needed supplies.
C Stewart FRSC
Northumberland, UK
Get your coat
From Martin White
Contrary to the impression given in the article ‘Fool’s gold’, the term ‘galvanising’ was proposed by Stanislas Sorel in his 1837 patent for the hot-dip coating of iron with zinc.
Sorel used the term to refer to the sacrificial protection that zinc provides to iron and steel through a hot-dipped coating. Even scratching the surface causes no noticeable corrosion, and the hard zinc oxide layer that eventually forms provides further protection. This protection mechanism was investigated in detail by Thomas Graham, first president of the Chemical Society. Zinc electroplating is often referred to as electrogalvanising, not because it uses electrolytic deposition but again because of the sacrificial protection it provides. The coating is much thinner and is rarely used for extended outdoor corrosion resistance.
Electroplating was invented in 1805 by the Italian chemist Luigi Brugnatelli and thus pre-dates, not post-dates, hot-dip galvanising.
For more information see www.galvanizing.org.uk
M White FRSC
Horsham, UK
From Anselm Kuhn
David Jones’ piece ‘Fool's gold’ was, as always, interesting. The piece could also have mentioned Sheffield plate – thin silver sheet mechanically rolled onto a copper base (no longer manufactured today) and its aureous counterpart ‘rolled gold’ or ‘filled gold’ (still widely used today).
These products are more durable than their electroplated equivalents and might be described as ‘gentle deceptions’. It should also be noted that all electroplated coatings below a certain thickness – typically 20µm – are porous. Therefore it is not always true that ‘a gold plated object should be indefinitely stable’, quite apart from the fact that high-carat golds can be soft and subject to wear.
Lastly, forgers are as resourceful today as they ever have been. ‘Solid gold’ coins and bars are skilfully drilled and the holes filled with tungsten, then re-sealed with pure gold. Their density is virtually the same as pure gold. Only techniques such as x-ray fluorescence can detect these fakes and all bullion dealers are well aware of them.
A Kuhn MRSC
Stevenage, UK
Matter of frack
From Frank Smith
Philip Robinson’s report on William Stringfellow’s survey of 250 fracking chemicals is old news. In April 2011, the US House of Representatives energy and commerce committee’s report Chemicals used in hydraulic fracturing drew attention to the hazardous nature of many of the 750 chemicals in 2500 different formulations used in this industry.
US chemical companies had come together in 2004 to enact what is known as the Louisville Charter for Safer Chemicals, but oil and gas seem to have been exempted from its recommendations. The worst aspect of this issue is the large number of proprietary products being used – and being kept secret! The situation in Canada is only marginally better.
For those of you living in the UK, Cuadrilla Resources, the most active company to date, has promised to use only four additives, of which glutaraldehyde might be of concern.
F R Smith, MRSC
Newfoundland, Canada
No comments yet