20 June 2013
12:34 IST
How Silver kills bacteria finally revealed
Silver ions disable bacterial respiration and destabilise the cell envelope, the mechanism behind wound dressings and antimicrobial coatings.
Silver runs through the archive as two stories that share one price. One is monetary, argued through the gold-silver ratio and investor positioning. The other is industrial and medical, and it is the one that has aged best.
4 restored dispatches 2011–2016 covered
Silver is priced as a monetary metal and consumed as an industrial one, and almost every disagreement in this silver news archive comes from that split. The investment dispatches, the silver bullion news of the period in practice, argue from the gold-silver ratio, from mine supply, and from the assumption that silver is a leveraged version of gold. The industrial dispatches count tonnes: electronics, brazing alloys, photovoltaics, catalysts, and the medical applications that turned out to be the archive's most durable subject. The two sets of dispatches rarely reference each other, which is itself an accurate picture of how the trade press covered the metal at the time.
The industrial side has aged much better. A 2012 forecast for the silver price is now only interesting as a record of what people believed; a 2012 figure for annual electronics consumption is still a usable quantity. That is the pattern behind the whole restoration, and it is the reason the silver news kept here is weighted toward measurement: the dispatches still worth opening years later are the ones that recorded a quantity rather than an expectation.
The headline figure, roughly 7,500 tonnes of silver into electronics annually against about 320 tonnes of gold, is worth understanding rather than just quoting. Silver has the highest electrical conductivity of any element, and in electronics it is used in quantities that are individually trivial and collectively very large: contacts, switches, conductive pastes, printed circuits, and the silver paste in photovoltaic cells. Almost none of it is recovered. Gold is used far more sparingly, in plating and bond wires, but is recovered much more often because it is concentrated in high-value components.
This asymmetry is the reason industrial demand supports the silver price more directly than it supports gold, and the reason the silver bullion news of these years reads as two files rather than one. Gold's industrial consumption is small relative to a jewellery and investment market measured in thousands of tonnes; silver's is roughly half of total demand. The demand split on the homepage sets the four destinations side by side for a single year, with each band's source named.
This page is current writing, so its mechanisms can be checked against the bodies that publish them. Figures inside the restored dispatches stay as filed.
Silver's antimicrobial use is older than the metals trade itself, and for most of that history it was empirical: it worked, and nobody could say why. The mechanism turned out to involve disruption of bacterial iron metabolism and respiration together with destabilisation of the cell envelope, with the practical consequence that silver ions can restore the effectiveness of antibiotics that resistant strains had learned to survive. This is the one subject in the archive where the 2013 reporting is still current, because the underlying science has not been overturned.
The exchange dispatches in this section are mostly about Shanghai, and they are mostly about margin. Raising the margin requirement on a silver contract is a way of making speculation more expensive without changing the contract itself, and an exchange that does it twice in a quarter is telling you that its volume assumptions were wrong. Read alongside the Chinese gold-exchange stories in the gold section, the picture is of market infrastructure being built and adjusted in real time, several years ahead of the regulation that would eventually govern it. It is also why the margin stories sit in this silver news archive rather than in a separate file on exchanges: at the time they were reported as price news, because that is what a margin change did to the price.
20 June 2013
12:34 IST
Silver ions disable bacterial respiration and destabilise the cell envelope, the mechanism behind wound dressings and antimicrobial coatings.
16 July 2012
15:17 IST
A mid-2012 case for silver built on the gold-silver ratio and industrial offtake, and what the next three years did to it.
9 July 2012
12:39 IST
How much gold and silver the electronics industry actually consumes in a year, set beside jewellery.
18 November 2011
11:10 IST
Shanghai tightened margin requirements twice in a quarter as silver volumes ran ahead of the exchange’s risk limits.
What the silver file holds from 2011 to 2016: price commentary and gold-silver ratio analysis, mine-supply notes, and the exchange rule changes that repriced the metal along the way.
Because that is where the evidence pointed. The single most durable factual claim in the whole archive is an industrial-demand quantity, not a price call, and the page that has held its search demand for more than a decade is about the antimicrobial mechanism rather than about investing. Roughly half of annual silver consumption is industrial, which is why a silver price can move away from a gold price for reasons that have nothing to do with monetary policy.
It is simply the number of ounces of silver one ounce of gold buys. It appears constantly in the investment dispatches because it is the cheapest available argument for silver: whenever the ratio is historically wide, the case writes itself. During the period covered here the ratio moved from the mid-fifties toward eighty, which means the argument was being made throughout and was wrong throughout, a useful thing for a dated archive to record honestly.
Yes, and the mechanism is understood. Silver ions disrupt bacterial iron metabolism and respiration and destabilise the cell envelope, which also makes some existing antibiotics effective again against resistant strains. That is why the metal appears in wound dressings, catheter coatings and water treatment. The dispatch on the mechanism is the fullest treatment in the archive.
Because volume grew faster than the exchange's risk framework had assumed. A margin increase is a blunt instrument for slowing turnover, and using it twice in a single quarter, as happened in late 2011, says the growth was not expected. Contract specifications explains what a margin actually is in this context and how it differs between venues.