09:51 – Barbara’s dad visited one of the retirement facilities yesterday and loved it. They keep one unit available for prospective residents to stay in overnight to see how they like the place. I suspect Barbara’s parents may give that a try.
It’s official. Greek living standards have already gone into the toilet, and are going to get worse. Prime Minister Antonis Samaras said, “Greek living standards have declined over the last three years by approximately 35%. A return to the drachma would immediately lower it by at least another 70%.” So, a 35% decline takes them from 100% down to 65%. A further 70% decline takes them from 65% to 19.5%. Samaras is an optimist. Their living standards are going to plummet whether they return to the drachma or remain in the euro.
12:27 – Duh. I’m currently making up Herzberg’s stain for the forensic science kits. It’s a rather involved process. I’d made up only a small amount when we were writing the book, but now I wanted to make up enough for at least 200 kits. (The stain is stable for years, but each batch differs slightly in its characteristics, so I wanted to make up a big batch to start with.) So I scaled things up a bit, which often comes to grief.
The first step is to make up a saturated solution of zinc chloride. Zinc chloride is extremely soluble in water. One liter of water will dissolve more than four kilos of anhydrous zinc chloride, producing about 2.5 liters of saturated zinc chloride solution with a specific gravity just over 2.0 g/L. Of course, zinc chloride is deliquescent, which means that standard trade material can be anything from truly anhydrous to a syrupy liquid. In practical terms, that means you don’t bother weighing out the solid zinc chloride; you just keep adding it to the liquid until some remains undissolved in the container.
So I started with 250 mL of distilled water, expecting to end up with about 625 mL of saturated solution, or about 1.25 kilos worth. I have some 1.5 liter PET wide-mouth bottles, which seemed ideal for mixing the stuff up. I even checked chemical resistance and found that PET was resistant to solid zinc chloride and saturated solutions of it. So I started by transferring the roughly 400 g of zinc chloride that remained in an open 500 g bottle to the 1.5 liter PET bottle, adding 250 mL of water, and swirling.
My first clue that I’d overlooked something was the steam condensing on the upper interior surface of the 1.5 L bottle. Ruh-roh. PET is indeed resistant to zinc chloride solutions. What it isn’t particularly resistant to is heat. Of course, I’d neglected to look up the heat of solution for zinc chloride, which turns out to be significant. It seemed possible that the solution would actually come to a boil. The bottle was softening as I watched it, deforming visibly. So I quickly poured the solution into a large polypropylene beaker. (I’d previously checked chemical resistance and found that in addition to PET, LDPE, HDPE, and PP are completely resistant to zinc chloride solutions.) PP is autoclavable, which means it can easily withstand the temperature of boiling water. It’s not possible under standard pressure for even a saturated solution of zinc chloride to boil above the softening/melting point of PP, so I knew the PP would be fine. Right now, I’m waiting for the solution to cool down before I add more zinc chloride. Now I know to use an ice bath.