That's why I am
giving them to you. If you had studied chemistry you would know them
without my telling. Just examine them and you will discover the secret.
You will see that all three are composed of the same elements, carbon,
hydrogen, and oxygen. Notice next the number of atoms in each element as
indicated by the little low figures on the right of each letter. You
observe that all three contain the same number of atoms of carbon and
oxygen but differ in the amount of hydrogen. This trifling difference in
composition makes a great difference in behavior. The less the hydrogen
the lower the melting point. Or to say the same thing in other words,
fatty substances low in hydrogen are apt to be liquids and those with a
full complement of hydrogen atoms are apt to be solids at the ordinary
temperature of the air. It is common to call the former "oils" and the
latter "fats," but that implies too great a dissimilarity, for the
distinction depends on whether we are living in the tropics or the
arctic. It is better, therefore, to lump them all together and call
them "soft fats" and "hard fats," respectively.
Pages:
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307