Good evening and thank you for joining me for another boring books for bedtime.

I hope tonight selection provides all the boredom your busy brain needs to quiet down and let you get some sleep.

So find a comfortable spot.

Adjust your volume,

take a nice deep breath in,

let it out slowly,

and off we go.

This evening let's relax with some science and return to the principles of chemistry by Dimitri Mendeliev.

Translated from the Russian by George Kaminsky, ARSMM of the Imperial Mint St. Petersburg, member of the Russian Physicochemical Society,

edited by T-A- Lawson, BSC, PhD.

Examiner in Koltar Products to the City and Guilds of London Institute Fellow of the Institute of Chemistry.

Published in two volumes in 1897 by Longman's Green and Co, 39, Paternostero, London.

Let's pick up where we left off in Mendelaeov's very lengthy introduction to the principles of chemistry.

Accepting the truth of the law of the indestructibility of matter, the question naturally

arises as to whether there is any limit to the various chemical transformations, or are they unrestricted in number?

That is to say, is it possible from a given substance to obtain an equivalent quantity of any other substance.

In other words, does there exist a perpetual and infinite change of one kind of material into every other kind, or is the cycle of these

transformations limited?

This is the second essential problem of chemistry, a question of

quality of matter and one it is evident which is more complicated than the question of quantity.

It cannot be solved by a mere superficial glance at the subject.

Indeed, on seeing how all the varied forms and colors of plants are built up,

...