Wednesday, April 6, 2016

Polarity testing in 1942

Popular Science editorial staff,  Evertybody's Radio Manual, Grosset and Dunlop, 1942

5 comments:

The Duke said...

And the great thing about the potato test is that you can eat it afterwards!

Mister G said...

Not after you soak it in phenolphthalein!

Anonymous said...

I challenge you to go to your local pharmacist and ask him for some 'phenolphthalein'. Tell him you need it for polarity testing. See what he says.

http://www.thefreedictionary.com/phenolphthalein

Anonymous said...

Further to previous -- that comment was meant entirely in fun. My warped sense of humour is occasionally, regretfully mistaken for denigration.

The Duke said...

It's an acid-base indicator! It's a laxative! It's two, two, two things in one! So, not only can it help you tell positive from negative, it can let you know if you're coming or going!