Equipment for power measurements on biological beings.

[antimony]

I am reading a book called "The Body Electric" by a doctor called Robert O. Becker and it is fascinating.
I has been on my "to-read"-list for a long time, but after i listen to a lecture by Jerry Tennant where he went through some of the background of electro therapy, and he recommended two books, and one of them was this one.

in the book there are much talk of measurements taken on various biological beings, like Salamanders, Frogs and plants, and i was just wondering what kind of equipment do you guys think these researchers are using when they are taking these readings?
I have taken my own voltage reading off my tounge with my DMMs, but i wouldnt trust that reading. Many of the studies Becker cites in the book goes back to the 60s and 70s and i guess their meters they used were top notch by their standards back then.
Their equipment would probably been much more sophisticated then the average $50 multimeters that we use today, or whats your thoughts on that?

Thanks in advance for your feedback.
I know this section of the forum is not used much, but the subject is really interesting, and imo something we should focus more on, as a collective. We could probably come up th something really great if we try as hard as we have done with the machines.

i bought a physical copy of the book, but it is available for download if you google the title. You know. 😉 If you are interested.

Ps. I am not a native english speaker, so there may be grammatical errors in this post, but its probably good enough .