10-23-2019, 01:56 AM
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#65 (permalink)
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| Chizpurfle
Join Date: Mar 2006 Location: underwater
Posts: 10,319
 x9
|  Stuck inside with Sirius | *Splish-Splash* | bamBAM | ☁ Spooktacular ☁
All seemed to be going well…perhaps suspiciously well, although perhaps that was just the advantage of having bubbling cauldrons over an open flame in this class. Claudine, Kaiser and Alexandre looked pretty much set up, with Bernadette and Phoebe not too far behind. “You’ll have an easier time if you put the paperclip on the paper first, and then hang it on splint,” he guided the first year Slytherin. Folding could work, but he much preferred this method.
Unfortunately for Blake, Noble did notice that beaker getting so carelessly knocked. “If the liquid went above the pencil line, you’ll need to start with a clean piece of paper. I suggest you hurry up and check, unless you want to staying here over afternoon break.” And Noble would know if Blake tried to pretend he didn’t need to when he did.
Alessandro perhaps wasn’t the only one wishing that Noble had instructed them to get all the equipment at the start. The Potions Professor watched Lucas zig-zag across the classroom for a moment, hoping the Gryffindor was paying attention to his surroundings as well as his work. The boy could be a little lax sometimes, and Cecelia looked just a tad impatient standing behind him to collect her beakers. Someone who was much more attentive in her potions work was Tina, and she seemed to be right on track today. He might have commented as much, if Eiji hadn’t voiced that question.
Noble smirked slightly at the fifth year Slytherin. “You’re welcome to test it if you wish.” He gestured towards the inkwell and quill by the planner on his desk. “Though I’m intrigued why you think I’d implicate myself, rather than just swap out my ink.” Given he knew exactly the evidence they’d be looking for in their mini investigation, it’d be easy enough to make sure the inks didn’t match.
With the experiments all ready and set up, it was time to explain the what and the why. “To recap so far: we’ve taken samples of ink on filter paper, and suspended those samples in two different solvents, alcohol and wizarding solution.” And if they didn’t have that set up in front of them by now, what had they been doing for the last twenty minutes?! “I previously said that ink is a mixture of different dyes and pigments, and that we’ll separate these using the solvents. We’re using two different solvents, since not all inks dissolve in the same solvent. A common example is ‘permanent’ pen. This usually means the ink is soluble in alcohol, but not in water…and therefore won’t just wash off in every day use.”
“Now, if you take a closer look at the filter paper, you’ll notice that even though we were extra careful to ensure that the top of the liquid stayed below the pencil line, the paper above the line is wet.” Hopefully they could all see what he was talking about. “As the solvent creeps upwards, it pulls any dissolved ink with it…and the different pigments in the ink move at different rates. Some, like the heavier or less soluble ones, will get deposited nearer the line…whereas other will get dragged much higher towards the top of the paper. The resulting image, showing the spectrum of colours separated vertically by the solvent, is known as a chromatograph.”
Noble moved to pick up two sample chromatographs from near the ransom note, and held them up. “Earlier, I took samples of ink from the ransom note, and made chromatographs in alcohol and wizarding solution just like you are at the moment. In a few minutes, when yours are ready, you can compare the traces of the colours on your chromatographs of the suspects’ inks with those I made of the ransom note. Any the match are strong evidence towards identifying the culprit, and finding out who stole the cookies. In the meantime, does anyone have any questions?”
He knew that was a lot of theory, but hopefully it’d be worth it. There were cookies on the line after all. ooc note: if your charrie doesn’t have questions (or even if they do!), they can go ahead and compare the chromatographs between the ransom note and inks from the suspects. If all has gone to plan, it should look something like the pictures below. If it hasn’t…then feel free to be your awesome creative selves!
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