Posts Tagged ‘gunpowder’

Gay eyeballs

Making gak eyeballs at Walden School

This last week was our final week of Fall Semester at Walden School, and for their final test my chemistry students planned, practiced, and presented chemistry demonstrations to their peers and to Walden’s elementary classes. Altogether five groups of students presented to the elementary school on Wednesday, Dec. 15 and the rest of the student teams presented on Friday, Dec. 17.

I’ve discussed my rationale for doing this in previous posts: that this is an excellent method for generating excitement about STEM in elementary students as they see their older siblings and high school students working with and presenting science. Certainly the younger students were very excited and attentive; they were eager to participate and asked good questions.

Raising hands

Students at Walden School participating in chemistry demonstrations

For me, though, the real reason for doing anything in my classes is always how it will benefit my students. Taking 3-4 days out of our curriculum to practice and present these demonstrations is hard to justify unless it has strong pedagogical advantages. The justification is this: as my students write up their demonstration scripts and outlines, as they practice talking about the science they are presenting, and as they prepare to answer questions from the audience they are thoroughly learning the chemistry behind their demonstrations. They are going beyond hands-on labs to share what they have learned, and that learning will be indelible.

Karlie and Sofia

Karlie and Sofia demonstrate hand warmers

The topics of the demonstrations had to related to the individual element/materials research project of one of the group members, which they are continuing to work on. Here’s what was presented:

Sofia, Karlie, and Jerry demonstrated the principles behind hand warmers by showing the rapid crystallization of sodium thiosulfate crystals that had been heated and then cooled down. They also talked about crystals in general.

Making gak

Mari and Casey help students make gak

Ryan and Casey, with help from Chelise, Lindsey, and Mari, demonstrated how to make gak (a polymer made out of white glue and borax powder). This is an old standby demonstration, and the kids really enjoyed it.

Copper demonstration group

Genny, Rachel, Jared, and Morgan demonstrate copper's properties

Genny, Rachel, Morgan, and Jared demonstrated aspects of copper chemistry. They handed around samples of copper ore (Rachel’s uncle is an engineer at Rio Tinto’s Bingham Canyon Mine in Utah) and showed a methanol version of a flame test (including copper salts). Jared demonstrated the alchemist’s dream reaction: turning copper into gold (actually brass).

Kinesthetic activity

Sid and Sam use a kinesthetic activity to demonstrate magnetic induction

Sam and Sid, with help from Josh, presented the idea of magnetic induction and discussed how modern electrical generators work. Sam actually built her own alternator and induction coil, and Sid presented on his research about the use of wind power to generate electricity. They also created a fun kinesthetic activity to show induction.

Burning magnesium

Karl and Nicona demonstrate burning magnesium

Karl, Nicona, and Tanner presented on the properties of the elements; they did a flame test as well, and demonstrated what magnesium ribbon looks like when burned and how fireworks get their colors. They also had sparklers for each of the students to try out.

Cabbage pH

Sonora, Dallas, and Morgan demonstrate cabbage pH

In class on Friday, the other groups presented their demonstrations. Sonora, Morgan, and Dallas presented the red cabbage pH demonstration that is one of my favorites.

Untarnishing silver

Mari and Holly demonstrate how to un-tarnish silverware

Courtney, Holly, and Mari showed how to untarnish silver using baking soda and aluminum foil. They even included a correctly balanced chemical equation, although we won’t be learning about those until we return in January.

Dry ice group

Libby, Lindsey, and Chelise demonstrate the properties of carbon dioxide

Chelise, Lindsey, and Libby presented the properties of carbon dioxide gas and dry ice. They showed how regular matches go out in carbon dioxide, but that magnesium burns even brighter when placed in carbon dioxide.

Olivia and Jace

Jace and Olivia explain the ingredients of gunpowder

Jace and Olivia talked about gunpowder, how it is made, and why it is dangerous. Jace has experience working with black powder (he has his own muzzle loader – this is Utah, after all) and he created some raw gunpowder, which he burn outside. They also demonstrated the “fire writing” demonstration of drawing on a piece of paper with a saturated solution of potassium nitrate, then touching a wooden splint to the edges of the writing to see it burn letters through the paper.

Josh and Jess

Josh and Jess demonstrate the principle of density with salt solutions

Josh and Jess presented on salt solutions and how they can be used to determine the density of objects. They showed how an egg will sink in pure water but will float in salt water.

We also videotaped as much of the presentations as we could and took quite a few photos; those students that weren’t helping present helped with the photography.

Burning gunpowder

Burning gunpowder

When their demonstrations were done on Wednesday and Friday, my students were excited about what they had done and the feedback they’d gotten from the younger students. They still have to learn some showmanship and presentation skills (which we’ll continue to work on), but based on what I saw and what the elementary teachers reported, the science content was excellent. They and their peers filled out evaluation forms (and I will as well) so that they can improve on their presentations for the next round in January.

Golden pennies

Golden pennies

It was a lot of work to prepare for this. Now my lab room is a mess and I’ll need to take a day during Christmas break to clean up and re-organize (and I think I forgot to throw out the leftover red cabbage pulp that’s in my trash can, so I’d better go clean up tomorrow). But despite the work and the lost time, I’d say these demonstrations were well worth it. As we go through the second semester, the students will present at least twice more, including a final time at a back-to-school night for their parents. We’ll polish the delivery, add more science explanations, create slide shows and videos to supplement their demonstrations, and by the end of the year these will be incredibly well done.

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Historia Naturalis by Pliny the Elder

Historia Naturalis by Pliny the Elder

    This last week at Chemical Heritage Foundation I have begun to photograph some of the ancient books and manuscripts that are housed here. After researching CHF’s online catalog, I identified several books to start with including Pliny the Elder’s Historia Naturalis, Basil Valentine’s Twelve Keys, and others. The research librarians of the Othmer Library then located the books in the rare book storage and brought them up to the Jacobs Reading Room where I have been photographing selected pages. 

    The fun has come through the realization that I am handling books that are 400 years old or more. I’ve handled some old books before where the paper has become so brittle that you can’t turn a page without tearing the paper; I was very nervous about that happening here, but found that these older books actually hold up better than many of the books printed in the 20th Century. 400 years ago, if you could afford a book, you could afford to do it right, with high-quality paper and leather binding. The paper of these books has an amazing feel (this coming from someone who’s dabbled in drawing and painting) and can be handled if proper precautions are taken, such as resting the books on a special pillow to avoid stressing their spines and making sure my hands are clean and oil-free.

Pages on Love Potions from Trinum Magicum

Pages on Love Potions from Trinum Magicum

    Once I got over my nervousness at handling the books, I began trying to decipher the Latin and German. I’m not very good at either language, but I did run across some interesting things. In a compilation book titled Trinum Magicum, I found a section labeled “De Unguento Armario” which I believe means “Love Potion” (those Latin scholars out there please correct me!). The author (unknown) didn’t seem to be in favor of love potions, and listed some of the symptoms one could expect from their use, such as “Inanis vita” or an empty or useless life. On the right page he mentions a “contra toxicum” or antidote. It occured to me that this was a perfect thing to discover given that the sixth Harry Potter movie, The Half-Blood Prince, is coming out this week and love potions figure prominently in the plot. I half expected Romilda Vane to be hiding behind one of the columns at CHF. Certainly these books bear more than a passing resemblance to those in the library at Hogwarts.  One of the other books I’ve photographed even included a summary of the works of Nicholas Flamel . . . !

The Sixth Key, from Basil Valentine, 1626

The Sixth Key, Basil Valentine, 1626

    Two of the other interesting books I’ve photographed are both editions of Basil Valentine’s Twelve Keys (Zwolfe Schlussel) in German. In this work, Valentine, a Benedictine monk, describes the twelve steps for making the Philosopher’s Stone (shades of HP again) and describes these steps through twelve allegorical drawings that are rich in symbols meant to confuse the uninitiated. Although much of the work was probably written at least a hundred years after Valentine’s death, it was still fascinating to realize how seriously all of this was taken back then. The first edition was a 1626 version, with the illustrations printed from woodcuts. The second was a 1717 edition, much expanded, with the illustrations printed from engravings and much more detailed. It has been fun to compare the two.

1717 edition of Basil Valentine's The Twelve Keys

1717 edition of Basil Valentine's The Twelve Keys

    Meanwhile, my wife ‘Becca, my two youngest children, and I ventured out to Delaware to the Du Pont gunpowder mill on the Brandywine River near Wilmington. From 1802 through 1921, the mill used water power from the Brandywine to produce the best black powder in the United States. Eleuthère Irénée du Pont de Nemours was an apprentice to Antoine Lavoisier, the famous chemist who was in charge of French gunpowder manufacturing. When du Pont’s father found that American gunpowder was of inferior quality, his son was sent to build a gunpowder factory using the techniques he had learned from Lavoisier. By refining the raw materials further to increase their purity, adding automation to the compositing process (where the saltpeter, sulfur, and charcoal were ground up and mixed through water power and rolling mills), and by improving the consistency of size and finishing of the powder grains, the Du Pont company became the leader in gunpowder manufacturing. They expanded into polymer manufacturing and other materials and are a leader today in the chemical manufacturing industry.

Water turbine at Du Pont gunpowder mill

Water turbine at Du Pont gunpowder mill

    To run the mills, a diversionary dam was built on the Brandywine to push water into a mill race that had less fall that the river. Along the mill race, headgates allowed the water to be diverted onto overshot waterwheels and later onto water turbines (shown here) to run two rolling mills each. Huge metal wheels rolled around in a trough, where the correct mixture of ingredients had been placed, until they were ground to a fine powder and thoroughly mixed. The powder was then compressed into cakes to increase its density (and power), then broken up into same-sized grains and glazed, then packaged and stored in a magazine far from the processing plant. Each of the mills was built with three strong stone walls, a flimsy roof, and an open fourth wall facing the river. In case of an explosion (which happend fairly often) the force of the explosion would go out over the river.

Gunpowder roller mill

Gunpowder roller mill

    All of this water-powered machinery required considerable maintenance, and there was a full machine shop with all the needed equipment also water powered through a system of shafts and belts. Gear cogs and other parts could be cut or repaired in this shop. One particularly interesting device was a transmission system for a variable drill; the two cones seen here are almost but not quite touching. The belt in between creates a point of contact and can be moved left or right to speed up or slow down the drill press, which runs off the belt at far right. I’ve seen similar belt-driven milling equipment at the Tintic Mining Museum in Eureka, Utah but it is all sitting outside rusting. Here at Du Pont’s Hagley Museum it was all in working order.

Transmission system for variable speed drill

Transmission system for variable speed drill

    Finally, here is a sample video of the Synthetic Diamond Manufacturing project, as promised. In this clip, Francis Leany, the Product Development Manager for Novatek, tells the story of how H. Tracy Hall invented the belt apparatus that successfully created the first artificial diamonds in Dec., 1954. I hope you enjoy it!

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