Have you ever wondered where your food comes from? Ever wondered about the quality and looked at the labels? Well they may or may not be of any help at all. Recently I bought a Nashi pear with “manufactured in China” on the label. Just poor English? Or perhaps unwittingly very correct English?

The recent audit of the controls on imported raw frozen prawns into Australia ( has highlighted for me some of the biosecurity problems there, with a number of large import companies in Australia caught systematically “gaming” the biosecurity system to bring in containers of frozen prawns that avoided border checks and testing.

The reality is that food is a global commodity. Many New Zealand foods are sourced overseas or are sent overseas for processing before being returned. Back in 1994, I was involved in certifying the condition of Alaska Pollack exported from New Zealand to Iran. For those unfamiliar with fish, Alaska Pollack come from the Bering Sea, near Alaska, not the Southern Hemisphere – and the fish had been caught by Russians, sold to another party, then a NZ company and finally to Iran – without ever having left the hold.

In 2012, over ten thousand German schoolchildren in 5000 schools sickened after eating strawberries in their school lunches. China is now the world’s largest supplier of strawberries, and 44 tonnes of Chinese strawberries were bought by a European company Sodexo – a large food distributor that supplies lunches to German schools. The strawberries were likely sourced from China because they were cheap. A quick check on this week (March 2018) shows that frozen strawberries can be bought ex China for US$100 a tonne,

Similar issues are likely to be occuring in New Zealand. New Zealand exports about 8000 tonnes of honey a year, yet “genuine” NZ Manuka honey ex china can be procured at $US 1789 a tonne, the supplier can supply 50 tonne per day. See

Or another supplier can supply 500 tonnes a month from and a bit cheaper too. Of course, you will need labels, and alibaba can supply those as well:

Alternatively I could buy NZ 26% butterfat milk powder. Now the Global Dairy trade price is around US$3623 a tonne but NZ whole milk powder is available ex Poland, 20 000 tonne per month for US$500 a tonne.
Austrian and French companies are advertising similar prices at the moment. So, I could potentially buy the cheap full cream milk powder, 16 tonne per container, route it through Auckland and make a little profit on the side.

Which gets me back to prawns. Why would major importers want to actively avoid biosecurity checks on their product? Prawns in Australia, as in New Zealand, are retailing at around $15 a Kg, and yet prices on the international market for shrimp (which we and Australians call prawns) currently start at around US $3 a tonne (that’s right – three dollars a tonne). The potential profits are significant, however, to maximise profit, quality (such as being infected with unwanted exotic viruses) is potentially sacrificed.

The problem for MPI is having the resources and expertise to detect and counter “gaming” of international commodities on such a huge scale.
Brian Jones


When your child turns nine or ten years of age….

by  on June 17, 2018

When your child turns nine or ten years of age, perhaps you may wish to interest him or her in science. Recently, my son turned eleven and, like all kids of his age, he has been exposed to some elementary science and mathematics at school. Like many people trained in the sciences, I have tried to guide him a little in mathematics and science, and have sought to extend him beyond the regular school curriculum in algebra and geometry. I have even taught him some simple computation and coding in the statistical and graphics programming language R (which originated here in New Zealand) and introduced him to Excel, teaching him about Excel functions, continuous and categorical variables, filtering data, sorting data and pivot tables, on the basis that skills in Excel will prove invaluable later on. In describing science or mathematics to my son, I have no hesitation in using Google, and in general I believe that there’s no major harm in using Wikipedia for kids!

The other day at Westfield Plaza, Lower Hutt, I bought a 64 mm triangular prism made by the US company The Light Crystal ( I wanted to tell my son about some basic science, in this case the splitting of light into the colours of the rainbow, allowing him to use the prism to split light, and adding human interest through the story of Isaac Newton and his scientific work at the time of the plague.

This epidemic occurred in 1665 and 1666, and was the last major outbreak of the bubonic plague to occur in England (though smaller scale outbreaks did occur in later times). Wikipedia tells us that this particular epidemic killed perhaps 100,000 people, roughly a quarter of London’s population, in a space of 18 months. The plague was spread by the Yersinia pestis bacterium, which is transmitted through the bite of an infected rat flea. Actually, Newton was forced to leave Cambridge for two years because of the plague, and so his work on the splitting of light was put on hold for that period. I thought that this story, even with its regrettable outcome for so many people, could nevertheless provide historic context for a young child encountering a fundamental principle of science for the first time. And so  – after talking about the plague, we got to the topic of the colours of the spectrum!

We browsed the Internet and sourced the above two pictures using Google Images – Newton splitting light and a nice diagram of light refracting through a prism.

The following two photographs were kindly sent to me by Brian Jones, member of Council of the Royal Society of New Zealand Wellington Branch.

Here we see Woolsthorpe Manor in Lincolnshire, where Newton stayed when Cambridge was closed by the plague and where he did most of his work on light. He had a little bedroom and study on the first floor, with a big fireplace for warmth. The living space was separated from the hay loft by a simple clay plaster wall.  There was no bathroom or toilet as we know it. The toilet was outside, and the only washing facility would have been a large bowl.

The apple tree in the photograph above is supposed to be THE tree – whose falling fruit provided Newton with the clue to gravity.

The point is that Newton didn’t have a fancy laboratory. His family was very poor, even by the standards of his day. However, he used observation and had a questioning mind – attributes that we all have if we wish to use them!

Back to our discussion of Newton’s work! We also used Google to source some of the text of Newton’s original work on dispersive refraction (Philosophical Transactions of the Royal Society, 1671, page 682). A very good web-site to source Newton’s original writings on optics and which provides clear accounts of Newton’s work is this one from the University of New South Wales (UNSW):

Let’s quote from Newton:

I procured a triangular glass prism, to try therewith the celebrated phaenomena of colours. And for that purpose having darkened my chamber, and made a small hole in the window shuts, to let in a convenient quantity of the sun’s light, I place my prism at his entrance, that it might be thereby refracted to the opposite wall. It was at first a very pleasing diversion to view the vivid and intense colours produced thereby.

A little later in the same text we learn that certain laws of refraction were already around at the time of Newton, but the challenge was to explain the laws of refraction to my own child. So, we took the prism outside on a very sunny morning in our back garden in Eastbourne. There he held the prism to the sun and created his first spectrum.

Here he is, casting a spectrum very successfully onto a painted wooden post on the morning of Saturday 25 February 2017. In the above photograph, he is holding the prism in such a way as to cast the component colours in reverse order, and thus blue and violet appear above orange and red. However, that morning he could see that blue and violet light was refracted more than red and orange.

Others before Isaac Newton had known that a prism separates sunlight, that oil on water gives rise to concentric rings of colour, and that bubbles can do something similar. Today, we have clear descriptions on how multiple reflections, refractions and transmission of sunlight through raindrops give rise to rainbows. My first clear description of the formation of rainbows was kindly provided by Professor John Lekner (of Victoria University) in an advanced physics class many years ago, and I think that I remember Professor Lekner telling us that, when we see a rainbow, in fact each of us has his or her personal rainbow because each of us observes from a slightly different location.  I always emphasise this point to my son or to friends when we encounter a rainbow!

However, Newton was the first to explain clearly that it is refraction that causes sunlight to separate into its various colours (frequencies or wavelengths) and that each frequency or wavelength is refracted at its own unique angle.

Newton also showed that a second prism could recombine the colours to produce white light, and he showed that each colour is unchanged when passed through a second prism. So, while white light can be broken into component colours, none of those colours can be decomposed further.  That’s interesting!

After Newton it became clear that white light is composed of light of different colours (frequencies and wavelengths), and that each colour is refracted differently. The different colours are the manifestation of light of particular frequencies or wavelengths, and the colours are refracted at different angles after passing through the prism. We refer to the separation of colours as dispersion.

In the UNSW web-site we learn that the medieval rainbow had only five colours: red, yellow, green, blue and violet, but that Newton added orange and indigo:

“ — so that the colours would be “divided after the manner of a Musical Chord”

(I. Newton in Opticks 4th edn, 127 (William Innys, 1730)”.

Though not addressed in Newton’s work (at least not addressed by him in any text or web-page I have seen), I nevertheless explained to my son some physics that is commonly introduced at senior secondary school – the notion of refractive index. Any sixth form or NCEA Level 2 Physics text will tell you that the refractive index (n) of a substance, like glass, water or air, depends on the speed at which light travels in that substance, relative to its speed in air. Specifically, it gives the ratio of the speed of light in a vacuum (c) to the speed of light in the substance (v). So, we have a simple formula for the refractive index that even a young child can understand:

n = c / v

Now we can explain that the refraction (bending) of a particular frequency or wavelength of light, as it passes from one substance to another (e.g. from air to the glass prism), depends on its refractive index, which itself depends on the extent to which the light slows down in the second substance.

The two of us enjoyed the following videos:



That’s as far as I went and perhaps that’s about as far as we can go with a young child who is not yet of secondary school age and who is encountering the splitting of light for the first time. Actually, when I purchased the prism, I also purchased a gyroscope with the intention of explaining angular momentum – but that’s another story!

Please feel free to give feedback on introducing science to kids.

David Lillis

25 February 2017

The author wishes to thank Chrissy Boulton, Lucy Forde and Brian Jones for contributions to this blog.


The Discovery of Science, a blog by Brian Jones

by  on OCTOBER 15, 2017

What has the little village of Mareham-Le-Fen in Lincolnshire got to do with New Zealand? Why is Horncastle of interest, and whoever heard of Revesby? Yet all these names have a direct bearing on New Zealand as we know it. But it’s not only a story of the district, it’s a story of a man who was an avid collector of “bugs” and “weeds” and who had a huge impact on the world around him.

In September we stayed with our daughter’s family at Mareham-le-Fen, a village of 600 people 10 miles from Horncastle and about the same distance from the even smaller village of New York (the real one, not the cheap American copy). I’m guessing this is the area the American founding fathers came from, names like “Boston”, “New York”,“Bunkers hill”. If you play a musical instrument, you too can play for “The Boston Orchestra”.

Figure 1. Main Road, New York

pic 1

There is not a lot to do in the village, there is a general store and post office that looks like a set from the 1980s sitcom “Open all Hours”, a 14th century stone cross and the pub (a free house) dates from the 17th Century. Nice timbered cottages nestle alongside horrible 1980’s brick housing estates and a church that was 13th century until it had a ghastly Victorian rebuild. In the church graveyard is an interesting tombstone to a certain James Roberts who died in 1826 and who had sailed in the Endeavour with Captain Cook.

So – who was James Roberts and how did he end up in the Mareham-le-Fen cemetery? A check of the ships complement shows that he was a civilian on the voyage listed as “servant” to Joseph Banks.

Figure 2. Tombstone of James Roberts

pic 2

A bit more digging revealed that the Banks family estates were in Lincolnshire, and the house that Joseph Banks grew up in was Revesby Abbey, literally a mile or so away. Many of the family retainers, it seems, lived in Mareham-le-Fen, which explained the presence of the tombstone. No doubt of an evening Mr Roberts told many tales of his voyage to locals at that 17th century pub.

But where was Revesby Abbey? There are nice Victorian gates on the A155, but they front an empty field. The current Abbey was built at the same time as the gates, in1845 and like so many English manor houses was acquired by the military during WWII, trashed by troops and never repaired.

But it’s not the Revesby Abbey that Banks knew, it’s not even in the same place. It turns out that the Abbey lived in by Joseph Banks was left empty after his death, and by the time his will was settled was deemed uninhabitable and demolished. However, the “long pond” built by Joseph’s father and subsequently renamed the “kangaroo pond” still remains.

But traces of Joseph Banks are everywhere, once you start looking. Banks had a townhouse in Horncastle (as far as we know he never lived there but it must have been useful as a base.

Figure 3. Joseph Banks house in Horncastle, ground floor now shops.

pic 3

He was instrumental in getting legislation passed that alienated the “commons” lands around Horncastle, much of the land ending up in his estate. The reason was “to increase productivity of the land” though I’m not sure the people of Horncastle, who lost their grazing lands, would have been impressed. He was also on the committee that drained the Fens (peat bogs) to produce arable land for sheep “Lincoln longwools”. Today, though, there is hardly a sheep in sight – all the land is devoted to market garden crops, picked by migrant workers and destined for the tables of the EU. He built mills along the coast to process the wool, and dredged the river so that it was navigable from the sea to Horncastle which then became a port. He also had a town house in London and every November he would pack up his household and travel to London for the annual meeting of the Royal Society.

The young Banks was an inveterate naturalist. Schooled at Eton (his school nickname was “Shanks Banks”), he was home in August and September, exploring the local Fens (peat bogs), chains of shallow meres with reeds, birds and fish. As a 14 year old he was already paying the local women 6 pence for every example (with explanation of properties) of the medicinal plants they collected in the Fens for sale in markets. His key text at the time was a battered copy of Gerard’s Herbal or The Generall Historie of Plantes” *(1597 )

pic 4

He collected and described everything he found – insects, plants, shells and fossils. There are stories of him, laden with collecting gear, being chased off lands by angry farmers little realising that the teenage with the jars and net was actually son of their landlord. Sons of gentry just didn’t do that sort of thing! He struggled at Latin until he realised it was necessary for describing his plants, then embraced it afresh but he never took to ancient Greek.

He was, in 1760 when he was 17, “sent up” to Oxford University. University then was far different from the degree factories of today! The Professor of Botany there, one Dr Sibthorp had given only one lecture in 36 years so Joseph arranged for (and paid) the botanist Israel Lions from Cambridge to be his private tutor Israel Lions was not only a botanist but an astronomer, which no doubt further broadened Josephs interests. During his first year his father died, and Joseph inherited the lands, titles and an income of 6000 pounds – which put him into the top 5% income.

In 1763 he became a reader at the British museum, working in partnership with Dr Carl Solander. He was still active in Lincolnshire though. In 1764 he was elected a General Commissioner for the 4th District(West and Wildmore Fens) charged with “maintaining the dykes and ditches, retaining water for cattle, regularly hooking, roding and scouring them (i.e keeping them free of weeds and mud) and building oak horse bridges over them”. It would seem that the Commissioners bankrolled the maintenance themselves and levied the landholders to recoup the money. No doubt Joseph’s extensive knowledge of the area and its flora and fauna was put to good use.

In 1776 he met up with an old school friend from Eton, Constantine John Phipps – then a Lieutenant in the Royal Navy, as a consequence Joseph, then 23, obtained permission to sail on HMS Niger on the Newfoundland Fisheries patrol from April 1766 to January 1767, taking with him his 19 year old servant Peter Briscoe. Joseph was often seasick but while away he collected in Newfoundland and Labrador – not only plants. He collected a scalp off the Indians, he wrote accounts of the English and French Fisheries, the habits of the fishermen, recipes for chowder and for spruce beer. Nothing escaped his interest – he was also learning the Guitar as we learn from his letter to his sister “How do you think I have spent my Leisure Time since I have been here Very Musically I can assure you I have learnt to Play upon a new Instrument as I have Forswore the Flute I have tried my hand upon strings what do you think it is now not a fiddle I can assure you but a Poor innocent Guittar which Lay in the Cabbin on which I can play Lady Coventries minuet & in Infancy &c: with Great success”

During his absence he was elected a Fellow of the Royal Society, nominated by Dr Charles Lyttleton, Bishop of Carlisle and Lord of the Manor of Horncastle, and Richard Kay, Later to be Bishop of Lincoln, who was a fellow botanist. Banks was described as “versed in Natural History and Botany and other branches of literature and likely (if chosen) to prove a valuable member”). Prophetic words! He was admitted on 12Feb 1767. That year he also wrote requesting his horses to be sent from Revesby to London, as soon as the roads were clear of snow. A young 14 year old James Roberts came down with the horses, and was to remain in service with Joseph for the rest of his life, including accompanying him on the voyage with Cook in 1768.

Brian Jones, Vice-President of the Royal Society of New Zealand Wellington Branch.

*And still available to read at: