# The library assignment

My high school chemistry teacher offered points for a weekly question he posed. Sometimes it was about chemistry, sometimes about science, and sometimes just random subjects. Unfortunately, I don’t remember any of the questions.

These questions were not the recitation of simple facts, and the answers weren’t things that anyone would know off the top of their heads. They were designed to force us to use various (pre-Internet) information sources to discover things. Although I never asked the teacher how he designed questions, I’m guessing that he started with the resource he wanted us to discover.

And, as part of this exercise, he offered no help or guidance. Again, this was by design.

As an undergraduate, we had to do various searches to find the source of information. For example, the molar mass of carbon is easy to find on the periodic table, but why is it that number? What’s the citation?

These things easy once you know how to use a library (pro tip: ask the librarian, and universities typically have special science librarians). You quickly find that there’s not a single source of truth. There’s a chain of truth, from the original measurement to various refinements of it.

There are various tricks to this. For example, suppose you have one paper that gives a new value of the molar mass. You can take that paper and find everything that cites it. There are long lists (in books!) of this. But, there are also lists of reverse citations. Put those two together and you can get to pretty good survey of the literature.

But, there’s another advantage to this. Sometimes the meta-information is wrong. Sometimes it’s a misprint, sometimes it’s a quirk of the particular journal, and sometimes it’s just a mistake. Solving those problems is educational. For example, the article doesn’t appear in the issue noted in the citation. Often, the year will be right (or close). So, you check the contents for all issues in an edition, and maybe the previous year (say, for submission dates and actual publication dates).

These skills are exactly the sort of thing you should learn from college: the examination and evaluation of primary sources. If you didn’t learn this in college, no matter the subject, you wasted your money and your professors cheated you.

When I taught chemistry in graduate school (intro and analytical), I had my own version of this. I required all lab assignments to include the total cost of the chemicals used and any special shipping requirements. If the chemicals were poisonous, they had to note the LD50 (lethal dose 50, where half the sample will die from that dose).

I got in a bit of trouble over this because professors thought I was harsh, but overall, my students did much better than all the others. Most professors just wanted to skate through their teaching assignments without any student discomfort. But, I wanted to actually teach so that people learned things. Those are different goals, and one of the main reasons I’m not in academia.

The extra lab report info is a fairly easy task: look in the chemical catalog and note the price and shipping instructions. There was a little bit of math to convert the bulk prices to the quantities used, but that shouldn’t be a big deal. Additionally, suppose you needed 5 grams of something, but could only order a kilogram? What’s the actual cost instead of the apparent cost?

The LD50 came out of the Merck Index (yep, the drug company). Sometimes there was an LD50 for humans, but most likely it was the LD50 for rates.

Some students complained about this, because like my high school chemistry teacher, I wouldn’t help them with this part of the assignment. They either had to figure it out themselves or get help from a classmate. Some people didn’t like the stated goal of self discovery. “When you get a job, you are going to have to do things that no one knows how to explain to you.”

In analytical chemistry, I ramped up the problem to include puzzles that required them to use particular resource. For example, here’s a bag of 100 pennies. You can’t look at the pennies, but you have to tell me how many are pre-1982? The Lange’s Handbook of Chemistry had various metallurgic tables for world coins. The US penny changed its composition in 1982. So, you have a set of parallel equations—one per variable. There are two variables and two equations:

\begin{align*} W_x &= ... \\ W_y &= ... \\ W_{total} &= ... \\ \\ x + y &= 100\\ W_x x + W_y y &= W_{total} \end{align*}

## A life skill

There are many books like this, for almost any subject or domain. You should learn to use the basic tools of your trade. As a writer, I’ve fought back against copyeditors by using Garner’s Modern English Usage, The Chicago Manual of Style, and various other tools they spout but don’t actually read. But, you need to know those exist and how to use them.