Tuesday, 25 June 2013

Burns and basilisks

I was working at my laboratory bench in the University when I first noticed sharp pains across the inside of both forearms and, when I looked at my arms, I was a bit shocked to see several lines of what appeared to be acid burns. My first reaction was to wash my arms and then go back to the bench to see if acid, or some other chemical, had spilled and accumulated along the edge where I had been leaning. There was no evidence of any liquid, so that wasn’t the explanation.

I went to the Occupational Health Unit for their advice and they agreed with me that it looked like I had placed my arms, on several occasions, on the edge of a bench where there had been a spill of a corrosive chemical. That would result in the lines of burns which were so evident. After the consultation, they recommended that I should go to St Thomas’ Hospital, which had a Dermatology Unit and where I could get further advice. Visiting hospitals is never much fun and I was apprehensive about what they might say but, fortunately, I was seen quickly by a member of the nursing staff and she asked me a few questions and then made a rapid diagnosis. One of the questions was whether we had any rue (Ruta graveolens) growing in our garden and she also asked if I could remember having touched it. Well, that morning we had indeed cut back a large rue bush and I must have brushed my arms against the sappy stems as I gathered everything up. It was a beautifully warm and sunny morning and it was a pleasurable little job before I set off to work by train and bus. The nurse then explained what had happened.  Sap from the rue had become smeared on my arms, making several invisible lines, and these had then become exposed to the sun, causing changes to the chemistry of the sap and thus resulting in the appearance of weals after several hours. She gave me some cream and, within a week, there was no trace of my encounter with the plant. I was fortunate, as one case involving a 12-year-old who had rubbed rue on his skin as an insect repellent required a hospital stay of 5 days. 1

From ancient times, rue has been used in herbal medicine, in addition to its value as a culinary herb. It was often administered in water, oil, or wine (sometimes with the addition of other components) and Culpeper advises its use against fever, flatulence, removing intestinal worms, stopping nosebleeds, easing earache, removing warts and in curing other skin conditions. Rue also “helps the gout or pains in the joints, hands, feet or knees, applied thereto” 2 In conclusion, Culpeper writes: “It helps disorders in the head, nerves, and womb, convulsions and hysteric fits, the colic, and weakness of the stomach and bowels; it resists poison, and cures venomous bites.” 2 The role of rue as a deterrent against fleas and other pests is also well known in folklore and its properties were said to be appreciated at the time of the Great Plague. A herb of wide-ranging value it would seem, but none of the treatments with rue, or its extracts, use the burning effect created after exposure to strong sunlight.

There is an interesting mythological association between rue and burning that may have arisen from the effects of phytophotodermatitis, the condition being known (although not by that name) in the Ancient World. 1 Basilisks were snake-like creatures described by Pliny the Elder, the Roman author and Natural Historian of nearly 2000 years ago. In time, they were portrayed as reptiles with wings and with the head and legs of a cockerel. Basilisks could kill with their stare, or by breathing on organisms, causing all to shrivel and die. There were three exceptions: cockerels (whose crowing caused basilisks to flee - is that why basilisks developed cockerel-like features through time?), rue, and weasels (especially if they had eaten rue, or were wrapped in it as in the illustration below). I cannot explain the role of the cockerel, but was the resistance of rue to the burning breath of a basilisk, or in conveying protection to weasels, based in some way on the known effects of the plant on skin, after the skin is exposed to sunlight? Such an effect, delayed as it is, would provide good material for mythology and we love fanciful explanations of the unknown.

1D.J.Gawkrodger and J.A.Savin (1983) Phytophotodermatitis due to common rue (Ruta graveolens). Contact Dermatitis 9: 224.

2Nicholas Culpeper (1880) Culpeper’s complete herbal: consisting of a comprehensive description of nearly all herbs with their medicinal properties and directions for compounding the medicines extracted from them. London, Foulsham.

Friday, 21 June 2013

Gosse, Elgar and the wonders of microscopy

Philip Henry Gosse was at the forefront of popularising the use of microscopes and in his book Evenings at the microscope; or researches among the minuter forms of animal life,1 he writes: “Great and gorgeous as is the display of Divine power and wisdom in the things that are seen of all, it may safely be affirmed that a far more extensive prospect of these glories lay unheeded and unknown, till the optician’s art revealed it. Like the work of some mighty genie of Oriental fable, the brazen tube is the key which unlocks a world of wonder and beauty before invisible, which one who has once gazed upon it can never forget, and never cease to admire.” Even through this expression of the religious ardour that dominated Henry Gosse’s life, it is easy to feel his amazement at what he saw and he conveyed this both to his friends and, through the book, to a wider public.

Microscopy became a popular pastime of the Victorian middle classes, once quality microscopes became less expensive, and an industry then developed in supplying slides of mounted specimens, often having elaborate paper labels or covers.2 While Henry Gosse, as a zoologist of note, described animals and parts of animals through 21 chapters of vivid description and with 113 of his own illustrations in Evenings at the microscope, algae were also a major fascination for Victorian microscopists, and the most important of these algae were the diatoms. These single cells (which may also form colonies or filaments) live within a coat of silicates termed a frustule, having two opposed valves that are secreted by the alga. The coats have characteristics unique to each species and provide the diagnostic features used in their classification. Victorian slides of mounted diatoms show not only an interest in individual algae, but also in the arrangement of frustules into “artistic” patterns.3 This tradition continues today in the work of the brilliant Klaus Kemp.4

Looking at diatoms provided inspiration in some unusual quarters. In his article in Gramophone of June 1957, published to mark the centenary of Edward Elgar’s birth, the author and raconteur Compton Mackenzie quotes this exchange with Elgar: “'Not that I care,' he growled quickly. 'I take no more interest in music. You'll find as you grow older that you'll take no more interest in literature. The secret of happiness for an artist when he grows old is to have a passion that can take the place of his art. I have discovered the joy that diatoms [my emphasis] can give me. This miraculous world of beauty under the ocean revealed by the microscope is beyond music,' and he went on to expatiate on the exquisite patterns formed by these fossilised algae and the spiritual comfort that observation of them brought to his mind.”5 The conversation from which the quote is taken took place in 1923, when Elgar was 66 years old. Although a famous and great composer, Elgar was prone to bouts of self pity and the quote is a reflection of one of those moods, but no-one can doubt his fascination for microscopy, the same fascination that Henry Gosse had done much to popularise over sixty year earlier. (By the way, for those of you who enjoy coincidences, Elgar was brought up in High Street, Worcester, the same street in which Henry Gosse was born many years before).

In the Natural World, diatom frustules are found extensively in the sediments of water bodies, from ponds to oceans. It may be thought that the coats developed to deter predators, and some of the more spiky types may do so, yet diatoms are fed upon by zooplankton and other animals, just as are algal cells without that protection. The result is not only the sedimentation of the frustules of dead algal cells but also of the frustule-loaded faecal pellets of animals which have eaten the algae. All fall through the water and accumulate over the bed. By taking cores, we can therefore know which species have been present in the surface waters through time, just as we can record the presence of plants by the types of pollen we see in cores taken from soil profiles. The deposits of diatom frustules can be so packed that they result in “diatomaceous earth” or diatomite, familiar for its many applications in industry after it is extracted by mining, or the use of quarrying techniques. These, of course, are ancient deposits and will have lost the clear stratification which occurs over short time periods of hundreds of years and where the contents of the annual layers of sediment can be recorded. We use information from these strata to date accurately the appearance of various species of diatom that we know are indicators of certain chemical conditions, or temperature regimes. In this way, diatoms give us a means of recording changes over centuries and much research has focussed on this use frustules. For example, changes in the diatom flora occurred after the Industrial revolution in Europe, when acid precipitation became a major feature and lakes changed in water quality. They are also used to show changes which have resulted from global warming.

Such practical applications do not detract from the beauty of diatom frustules, so stunning when observed under the microscope, especially under special lighting. It is easy to comprehend Gosse’s conclusion that we are witnessing “the display of Divine power and wisdom” but, for those that do not believe in the chronology of events described in the book of Genesis, there is an equal, or perhaps greater, sense of awe. One is left with the question: How and why did diatoms evolve their many varieties? The fossil record shows that they have existed for tens of millions of years in forms that are recognisable today6 and we can only speculate on the steps that occurred in the evolution of the siliceous frustule before that. It’s the frustule that makes diatoms so popular and useful but that is only the covering of the living algae, which are so important in trapping carbon dioxide through photosynthesis and thus playing a major role in the metabolism of energy in fresh waters, marine coasts and the oceans.

1 Philip Henry Gosse (1859) Evenings at the microscope; or researches among the minuter forms of animal life. London, Society for Promoting Christian Knowledge.

Friday, 14 June 2013

Aunts and time

Most of us have been through the ritual of being taken to visit relatives when we were young. My earliest memories include those of going to the homes of various aunts (actually great aunts) in the early 1950s and then wondering how long we were going to stay. Their drawing rooms were dark, with lots of lace, china ornaments, aspidistras in large planters, sentimental pictures, and a characteristic smell. It wasn’t unpleasant, just different, and I was conscious of having to be well behaved (we were made very “presentable” for these visits), saying a few things and then tuning out of the conversation, about which I understood little.

In contrast to these routine visits, going to see one of the aunts was always a pleasure. Aunt Ede loved cats (see the picture below, taken in the early 1930s), had married Uncle Os when she was 66 (and I was 3), and was very happy with her companions. Aunt Ede used to accompany us on Nature walks in the surrounding countryside, while Uncle Os was busy in his workshop, in an atmosphere of oil vapour and pipe smoke. We would also see her in the town, always carrying her round wicker basket containing fish bought at the fishmongers and which was destined to be supper for the cats. Aunt Ede lived in a house named Malvernia (her family came originally from Malvern) and when we called she would always thrust money into our hands and make tea and provide cakes. A wonderful lady and, like me, a bit of an independent-minded sort. She never really recovered after Uncle Os died in 1965, but her joy at seeing me when I popped around to Malvernia during University vacations was touching. 

The last time I saw Aunt Ede was in a nursing home in 1972 and she asked repeatedly about the cats and whether they were being looked after. I suspect that, by then, the cats had been removed and it was a sad way to say goodbye to a remarkable lady, although I didn’t know that it was to be a final goodbye. I still remember Aunt Ede with fondness. She loved Nature.

The aunts seemed very old indeed to me when I was a boy, but I had only a few years of my own to compare against their many decades. For me, the future was full of unknowns, whereas the aunts knew what they had achieved and also knew that they did not have many years to live. Perhaps that’s why their conversation reverted to chat about other family members and that excluded me as I had no idea who was related to whom, and no interest in their lives. As far as I know, none of the aunts extended this interest into preparing a family tree, but doing so has become a popular hobby now that we have such easy access to data that help us in tracing ancestry. Genealogy is mostly an occupation for older people, as it provides a way of recording one’s place in history, although with the date of death still to be inserted, of course.

Most family trees go back two or three generations (those of Royal Families substantially longer) and the further we go back the less we know about the way of life of our ancestors. Is it possible to get a feeling for the lives of those, say, four or five generations back? We can get some information by visiting museums or preserved buildings, but that seems impersonal and contrived and the way of life of the occupants of the rooms displayed can only be imagined. If that is true of the recent past, how can we get a feel for life thousands of years ago? Probably not by looking at artefacts, montages or re-creations.

If that is a difficult question to answer, what about our understanding of geological time scales, where 10 million years is recent and where the origins of the Earth go back billions of years? These are just numbers to us and mean little, except as reminders that humans are very recent indeed on such time scales and our knowledge of the Universe, including our World, has been acquired largely within a handful of generations. It is an astonishing achievement and provides us with the best explanation of what we observe to have happened over unimaginable timescales and distances (with apologies to those who believe it was all created 8000 years ago). It doesn’t seem feasible that such a very recent species has been able, in a few hundred years, to explain so many things, just by using our Earth-bound mathematics, physics, chemistry and biology. What if we are wrong in our assumptions and there is a different, more fundamental basis for understanding time and space that awaits discovery? Will we then be able to gain a real sense of time?

Tuesday, 11 June 2013

Watching azure damsels

It’s the time of year in the UK when dragonflies and damselflies are emerging. The margins of ponds, streams and lakes start to harbour blue, red or other coloured damselflies, while their larger and variously coloured relatives, the dragonflies, fly over the water searching for prey insects. Yesterday, I was visiting ponds in Norfolk and came across many azure damselflies (Coenagrion puella), the bodies of males being a striking combination of blue and black, with the females rather duller (despite their common name, there are male and female damselflies). They were flying around the vegetation and occasionally perching and it was clear that some were newly emerged from the ponds where they had been living as larvae since last summer, as their colours had not developed fully. One adult, just minutes after emerging, became the victim of a spider, which grabbed the damselfly resting on a plant stem and took it to the base of the plant to be devoured later. A piece of “raw” Nature and one that reminded me that my love of watching damselflies and dragonflies is based on my very partial knowledge of how Nature really is, as well my aesthetic appreciation of the insects.

Dragonflies and damselflies (I’ll call them Odonata, as that is the name for the Order) are beautiful to look at, and are very well engineered, but that is not for my benefit. They have existed in much the same form as we see them today for well over 100 million years. We cannot comprehend such a period of time, but we are fairly sure that there were no humans for 99.8% of the time that the contemporary Odonata have been in existence. It is quite extraordinary to know that all the stages of their evolution, from a single cell to the complex insects we know today, occurred way before 100 million years ago: the development through larval stages, with moults to increase size; the ability to fly and change direction rapidly; the development of excellent vision; the different catching devices of larvae and adults. I could go on and on in making a list of features and they were all in place so very long ago, with the successful pattern being repeated through more than 100 million generations. Of course, there are some who cannot accept this view and among the more famous of these was Philip Henry Gosse, the excellent Victorian Natural Historian and author of Omphalos, 1 in which he explained that Creation occurred as described literally in the Holy Bible, over a period of days. To him, fossils (including those of the Odonata, some of which are of much larger forms than are found today) were part of that Creation and it is a view which is still held by some. 

The folklore surrounding damselflies and dragonflies is even more odd than the explanations provided by Creationists like Gosse. As their common name might suggest, it is the dragonflies, rather than their smaller and more delicate relatives, the damselflies, which feature in most folklore.  A review is given in Spinning Jenny and Devil’s Darning Needle by M. Jill Lucas 2 and the title of her book gives us a clue of what is to come. She has researched information from around the World and found that dragonflies may be associated with death (by them breathing on us, or by their sting - although the insects do not exhale and cannot sting) and they might be used by the Devil to “weigh people’s souls”. For those who enjoy fishing, the insects are a sign of good luck or bad luck depending on one’s country and, despite their negative religious associations, are regarded generally as being tokens of good luck, whether one is fishing or not.  In contrast, these “Devil’s Darning Needles” may stitch up the mouths of children who tell lies, the mouths of noisy persons, or the toes of those who sleep with their feet uncovered. It's all very confusing and there is much more on folklore in Jill Lucas’ book, which also covers the position accorded to dragonflies and damselflies in the Arts and as illustrations on stamps. It is well worth reading and shows us both the way in which the insects are appreciated and how extraordinary are our imaginations in making interpretations of the unknown.

I have always spent time watching damselflies and dragonflies. From childhood, it was something that I loved doing and, together with looking at wild flowers and collecting animals and plants from rock pools and streams, was part of my early interest in Natural History. As I describe in Walking with Gosse: Natural History, Creation and Religious Conflicts,3 the Odonata even became the subject of my undergraduate research project. Is it possible to have a favourite species? Probably not, as they are all beautiful and one cannot separate the insects from their location, which might be magical in the scented evening of a balmy summer’s day. However, if I had to make a choice, it would be the Blue-tailed Damselfly (Ischnura elegans) flitting over reeds. If I didn’t know better, I could believe that it was created just to give me pleasure and a sense of wonder.

1 Philip Henry Gosse (1857) Omphalos: an attempt to untie the geological knot. London, John Van Voorst.

2 M. Jill Lucas (2002) Spinning Jenny and Devil’s Darning Needle. Bradford, Wheelden Print.

3 Roger S. Wotton (2012) Walking with Gosse: Natural History, Creation and Religious Conflicts. Southampton, Clio Publishing.