By definition, an indicator is a substance that changes colour in different pH environments. Universal indicator is a brown-coloured solution—containing a mixture of indicators—that can be added to any substance to determine its pH. Like all indicators, universal indicator changes colour in different pH environments. At low pH, it appears red, and at high pH, it appears blue or violet. At neutral pH, it appears green. Universal indicator can form a continuous spectrum of colours that give an approximate reading of the concentration of protons in a sample.
Water and propan-1-ol are used as solvents. They are both polar and dissolve all the other ingredients in the solution. Sodium hydroxide (NaOH) is an alkaline solution that adjusts the pH of the universal indicator to ensure that each colour is shown at the correct pH value. It is necessary to add NaOH to the universal indicator because some of the indicator compounds (e.g. methyl red) are acidic themselves, which would affect the…
If you think about a modern scientist doing his job, you will probably imagine him/her operating complex and expensive cutting edge machines and computers, characterizing materials and structures through a SEM, and producing and disseminating evidences to support their theories and express their results in form of pictures, graphs and images obtained using sophisticated digital cameras and manipulated with innovative softwares. There is a good chance they will use a laser or, even better, a 3D printer.
For the youngest audiences in particular, it is very difficult to imagine that there was a time, when a scientist had to be good at drawing, or at least at finding someone able to do it in his place.
Early biologist, botanists, ethologists, and even chemists, were forced to use their artistic skills to understand and explain the rules of the world that they were trying to unlock. Some of them weren’t so scientific, in a modern sense, at the contrary their works are very imaginative, but they are still interesting, as the following books illustrations.
The changes in the way scientists produce images and share them within their community and the public, was the subject of a day of hands on activities and lecture at the Royal Society, last Saturday, the 25th of October. The title of the event was “The Big Draw: Drawing Science” and was part as The Big Draw festival,
Young children, and curious adults as me, were “pushed” to take inspiration from rare scientific illustrations pulled from the Royal Society archives, exploring areas where science and art overlap.
In addition to the importance that science illustrations have in documenting the path and development of some of the most important scientific discoveries and theories, they also suggest the hypothesis that drawing complex natural structure precisely, may help to better understand the details, and how they are related and interconnected to each other, forming a whole. In other words, producing your own images you will learn more about what you are studying.
Because children like drawing, involving them in making their own scientific illustration, copying original drawings, complete animals half drawn, or building mosaics with the basic crystals shapes, can be both educational and fun!
Children and their carers enjoyed a dedicated area with activities and workshops, try their hands at drawing animals, making their on pop-up book, or having a dinosaur named after them.
Personally, I found the activities very interesting and it would be a good idea to carried them out in a school, to be used in support to the science curriculum or during after school or summer club.
During the afternoon two lectures took place, in one of the beautiful rooms of the Carlton House Terrace.
The first one was lead by historian Dr Sachiko Kusukawa, tutor and Fellow in the History and Philosophy of Science at the University of Cambridge.
The focus of the speech was on the intersections of art and science in the 17th and 18th centuries. Professor Kusukawa explored sketches, engraving and paintings that gave background to some of the images on display, and explained how they were used by scientist to guide their studies.
The second lecture, was more informal, and I really enjoyed it. The title was “Dynamic collaborations”, and was lead by Brian Sutton, crystallographer and professor of Molecular Biophysics at the King’s College of London, and glass artist Shelley James, originally trained in textiles, at the Ecole Nationale Superieure des Arts Decoratifs in Paris and then deciding to explore the themes of perception and reality from a more personal perspective, she studied printmaking at the University of the West of England. This lead to developing new techniques for encapsulating prints in glass with support from the National Glass Centre in Sunderland and Arts Council England. The symmetry and quasi-symmetry of crystals inspired Shelley to produce her 2D and 3D glass works. Professor Sutton and Shelley engaged the public with a conversation about how they ended up working together and what the differences and similarities in their vision of crystals are.
In a passionate and inspiring explanation professor Sutton told us the story of the Penroses tyles and the discover of a very special type of minerals that lead to a very important Nobel price for Chemistry in 2011 . In fact in 1984 the team of Professor Schechtman found that a crystal of a rapidly cooled alloy of aluminum and manganese, was showing a 5 fold symmetry (the so called “forbidden symmetry”). The team’s description of the atomic structure of a metal alloy ultimately forced scientists to redefine the term “crystal.”
The 2011 Nobel Prize in Chemistry recognizes the discovery of quasicrystals, in which atoms are ordered over long distances but not in the periodically repeating arrangement of traditional crystals.
A new category of crystals whose patterns don’t repeat in the traditional way.
Have you ever heard about the Ig Nobels? Well, if the answer is negative, you definitely must find out more. The Ig Nobels are a very peculiar form of scientific award. In fact these prizes are awarded for achievements that first make people laugh then make them think.The Ig Nobel prize is handed out by the Annals of Improbable Research magazine at the Harvard University for silly sounding scientific discoveries that often have surprisingly practical applications.
Here it is the list of 2014 winners:
PHYSICS PRIZE [JAPAN]: Kiyoshi Mabuchi, Kensei Tanaka, Daichi Uchijima and Rina Sakai, for measuring the amount of friction between a shoe and a banana skin, and between a banana skin and the floor, when a person steps on a banana skin that’s on the floor.
NEUROSCIENCE PRIZE [CHINA, CANADA]: Jiangang Liu, Jun Li, Lu Feng, Ling Li, Jie Tian, and Kang Lee, for trying to understand what happens in the brains of people who see the face of Jesus in a piece of toast.
REFERENCE: “Seeing Jesus in Toast: Neural and Behavioral Correlates of Face Pareidolia,” Jiangang Liu, Jun Li, Lu Feng, Ling Li, Jie Tian, Kang Lee, Cortex, vol. 53, April 2014, Pages 60–77. The authors are at School of Computer and Information Technology, Beijing Jiaotong University, Xidian University, the Institute of Automation Chinese Academy of Sciences, Beijing, China, and the University of Toronto, Canada.
PSYCHOLOGY PRIZE [AUSTRALIA, UK, USA]: Peter K. Jonason, Amy Jones, and Minna Lyons, for amassing evidence that people who habitually stay up late are, on average, more self-admiring, more manipulative, and more psychopathic than people who habitually arise early in the morning.
PUBLIC HEALTH PRIZE [CZECH REPUBLIC, JAPAN, USA, INDIA]: Jaroslav Flegr, Jan Havlíček and Jitka Hanušova-Lindova, and to David Hanauer, Naren Ramakrishnan, Lisa Seyfried, for investigating whether it is mentally hazardous for a human being to own a cat.
BIOLOGY PRIZE [CZECH REPUBLIC, GERMANY, ZAMBIA]: Vlastimil Hart, Petra Nováková, Erich Pascal Malkemper, Sabine Begall, Vladimír Hanzal, Miloš Ježek, Tomáš Kušta, Veronika Němcová, Jana Adámková, Kateřina Benediktová, Jaroslav Červený and Hynek Burda, for carefully documenting that when dogs defecate and urinate, they prefer to align their body axis with Earth’s north-south geomagnetic field lines.
ART PRIZE [ITALY]: Marina de Tommaso, Michele Sardaro, and Paolo Livrea, for measuring the relative pain people suffer while looking at an ugly painting, rather than a pretty painting, while being shot [in the hand] by a powerful laser beam.
ECONOMICS PRIZE [ITALY]: ISTAT — the Italian government’s National Institute of Statistics, for proudly taking the lead in fulfilling the European Union mandate for each country to increase the official size of its national economy by including revenues from prostitution, illegal drug sales, smuggling, and all other unlawful financial transactions between willing participants.
Even though we know thousand of ancient pharmacological and cosmetic recipes from the Greek and Latin literatures, archaeological discoveries of actual drugs, especially in good conditions, to be characterized from a chemical and botanical point of view, are very rare.
What ingredients did our ancestors use for the preparation of their drugs?
In 1974 a discovery came to help giving an answer to that question. Off the coast of Tuscany the shipwreck of a Roman boat was discovered, and explored during the 1980s and 1990s. The most accredited hypothesis is that the boat, known as the Relitto del Pozzino (Pozzino’s shipwreck), dates 120-140 BCE and that was a trading ship sailing from the Asia minor and Greece areas, carrying wine, glass cup and lamps.
The vessel was laying about 18 metres underwater in the Baratti’s gulf, not far from the remains of the important Etruscan city of Populonia, a key port along trade routes across the Mediterranean.
Various pharmacological preparations were also found, together with a surgery hook, a mortar 136 wooden drug vials and in particular several tin boxes. These boxes, called pyxides, were subjected to x-ray examination. The analysis showed something interesting inside one of the pyxides: five circular medicinal “tablets”. Due to the fact that they were sealed, the “tablets” were in a good state of conservation and completely dry, even though they were resting on the sea floor for a very long time.
In 2012, a team of Italian scientist, belonging to the Chemistry department of the Pisa’s University and the Evolutionary biology of the Florence’s University, under the supervision of the Superintendence for the Archaeology Heritage of Tuscany, analyzed these remains, combining chemical, mineralogical, and botanical investigations. The scientists used the most modern analytical techniques, like scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), and gas chromatography/mass spectrometry (GC/MS), with the aim to clarify their compositions and possible uses.
In order to characterize the composition of the materials, fragments were sampled from a broken tablet with a scalpel, dived into subsamples, and stored in glass containers.
The results showed that the disks’ components were about 80% inorganic with zinc as the main element (75%), along with silicon, and iron, as minor elements. For the organic part the analysis pointed out to the presence of starch, that was a well known ingredient of Roman cosmetics, beeswax, a mix of vegetal and animal derived fats, including olive oil, pine resin, that may have prevented the oil from going rancid and opposed microbes’ growth due to its antiseptic properties.
Comparing the results of these analysis with ancient collections of pharmacological recipes, proves that zinc oxide and hematite were used together in the treatment of eye diseases, as shown in one of Galen’s treatise, Medicines according to Places.
“Cleaned Cadmia (zinc oxide), 28 drams; hematite stone, burnt and washed, 24 drams; Cyprian ash (i.e. copper), 24 drams; myrrh, 48 drams; saffron, 4 drams; Spanish opium-poppy, 8 drams; white pepper, 30 grains; gum, 6 drams; dilute with Italian wine. Use with an egg” (Galen, Compositions ofmedicines according to Places 4.8, 12.774 Khun).
The efficacy of zinc compounds in treating human diseases suggests that zinc carbonate and hydroxycarbonate were the active compounds in the formulation of Pozzino’s tablets. Zinc oxide was considered important from a therapeutic point of view. It was obtained during the casting of copper from minerals also containing zinc ores, as reported by Pliny the Elder in Naturalis historia, and Dioscorides in De materia medica, describing different qualities of cadmia collected from the vaults or walls of the furnaces during copper production. They wrote how this side-product was useful for the eyes’ treatment and for general dermatological purposes.
The compositions and the old recipes described above give very little clues about the way the remedy should have been prepared and applied. We can imagine that all dry products should have been crushed together in a mortar, diluted in wine and moulded into tablets, dried and dissolved in a liquid, as water, wine, or egg (as suggested in the Galen’s recipe).
In a previous study on the Pozzino’s tablets, a US team from the Smithsonian’s Centre for Conservation and evolutionary Genetics, carried out a genetic analysis of the vegetal materials contained in the remains. Comparing the sequences of DNA fragments to a genetic database, the scientists identified many plants, including carrot, radish, parsley, celery, wild onion and cabbage. The results of this research suggested a different theory for the use of the pills. They could have been used for gastrointestinal disorders, and taken by the sailors during their long trips. So, were the Pozzino’s tablets medicines meant to cure sore eyes, or for painful bellies? Whatever the truth is, these findings, studies and debates would help to enhance our knowledge of the sophisticated ancient pharmaceutical world.
I found this funny comics in an amazing website, xkcd.com! Check it out!
At the beginning I was reading the blog now and then (http://blog.xkcd.com/), but after a while I discovered the website with a big collection of comics, and I really liked it. Some days ago the creator of the blog, Randall Munroe, published a book, “What If?: Serious Scientific Answers to Absurd Hypothetical Questions”, that contains the best posts from the blog and along with brand new weird and wonderful questions. The British edition has been launched just the last 4th of September. I can’t wait to read it!