Chemical compounds and combinations

Water is H2O, hydrogen two parts, oxygen one,
but there is also a third thing, that makes it water
and nobody knows what that is.
— D. H. Lawrence (1885 – 1930), Pansies, ‘The Third Thing’.

I fell into a reverie, and lo, the atoms were gambolling before my eyes! Whenever, hitherto, these diminutive beings had appeared to me, they had always been in motion, but up to that time I had never been able to discern the nature of their motion. Now, however, I saw how, frequently, two small atoms united to form a pair; how a larger one embraced the two smaller ones; how still larger ones kept hold of three or even four of the smaller; whilst the whole kept whirling in a giddy dance. I saw how the larger ones formed a chain, dragging the smaller ones after them but only at the ends of the chain … The cry of the conductor: ‘Clapham Road,’ awakened me from my dreaming: but I spent a part of the night putting on paper at least sketches of these dream forms. This was the origin of the ‘Structural Theory’…

Something similar happened with the benzene theory … I turned my chair to the fire and dozed. Again the atoms were gambolling before my eyes. This time the smaller groups kept modestly in the background. My mental eye, rendered more acute by repeated visions of the kind, could now distinguish large structures of manifold conformation: long rows, sometimes more closely fitted together all twining and twisting in snake-like motion. But look! What was that? One of the snakes had seized hold of its own tail, and the form whirled mockingly before my eyes. As if by a flash of lightning I awoke; and this time also I spent the rest of the night in working out the consequences of the hypothesis.
— Friedrich Auguste Kekulé (1829 – 1896), quoted in the Faber Book of Science, 137-138 from Journal of Chemical Education, 1958.

Now it is one great object of this work, to shew the importance and advantage of ascertaining the relative weights of the ultimate particles, both of simple and compound bodies, the number of simple elementary particles which constitute one compound particle, and the number of less compound particles which enter into the formation of one more compound particle.
— John Dalton (1766 – 1844), A New System of Chemical Philosophy, 1808.

Carbide is made from lime and carbon in the electric furnace. When it is treated with water it gives the gas acetylene, the molecule of which contains two carbon and two hydrogen atoms. Acetylene can be easily made into a large number of other substances: acetone, alcohol, acetic acid, plastics, synthetic rubbers, etc.
— Sir Robert Robinson (1886 – ?), ‘Making New Substances to Order’, from Science Lifts the Veil, 1942.

[The Astronomer Royal] asked chemists to produce an alloy that (among other properties) should be light, expand little with changing temperature, be absolutely rigid and keep its shape well. It is probable that chemists will one day discover what metals should be mixed together in what proportions, and in what way, to produce the kind of alloy the Astronomer Royal wants.
— A. W. Haslett, Unsolved Problems of Science, London 1937.

Corresponding to the words ‘solvent’ and ‘solution’, some word is badly needed to express ‘the dissolved substance.’ The analogous word is evidently ‘solute,’ and it is as short and euphonious as the others. May I enquire why it is not in general use? Surely some one must have proposed it?

Leipzig F. G. Donnan
— Letter to Nature, December 27, 1894, No. 1313, Vol. 51, 200. (By 1939, Donnan was Manager and Vice-President of the Royal Institution.)

Salt from sea-water is made in the following manner. Near that part of the seashore where there is a quiet pool, and there are wide level plains in which the tides do not overflow, three, four, five or six trenches are dug, two metres wide, four deep, and two hundred long … all of the trenches are filled. Then the first basins are filled up from the nearest trench and left until much of the thin liquid is converted into vapour by the heat of the sun … and the remainder is considerably thickened. Then the water passes into the second basins, and when it has remained there a certain time, the gates are opened so it flows into the third basins, where it is all condensed into salt.
— Georgius Agricola (1494 – 1555), De Re Metallica.

The quantity of the different elements in sea water is not proportional to the quantities of elements which river water pours into the sea, but inversely proportional to the facility with which the elements in sea water are made insoluble by general chemical and organochemical reactions in the sea.
— Johann Georg Forchhammer, 1865, quoted in New Scientist, 13 June 1992, 31.

An unexpected conclusion may be deduced from this idea. As all electrolytes in extreme dilution are completely active, then the weak acids must increase in strength with dilution, and approach the strength of the strongest acids. This was shown by Ostwald soon afterwards to agree with experiments
— Svante Arrhenius (1859 – 1927), explaining his theory which earned him the lowest level of doctorate in 1884, and a Nobel Prize in 1903.

There once was a lady named Harris
That nothing seemed apt to embarrass
            Till the bathsalts she shook
            In a bath that she took
Turned out to be plaster of Paris.
— anon in W. S. Baring-Gould, The Lure of the Limerick, 137.

If now this new conception were only applicable to the explanation of the phenomena of electric conductivity, its value [would have been less]. But an inspection of the numbers of Kohlrausch and others for the conductivity of acids and bases, compared with the measurements of Berthelot and Thomsen on their relative strength with regard to their chemical effect, showed me that the best conducting acids and bases are also the strongest. I was thereby led to suppose that the electrically active molecules are also chemically active. On the other hand the electrically inactive molecules are also chemically inactive. In this connection I would mention the remarkable experiments of Gore, which were easily explained by the new manner of view. Concentrated hydrochloric acid [i.e. hydrogen chloride gas], free from water, has no action on oxides or carbonates. Now this hydrochloric acid contains, therefore, no (or extremely few) active molecules, and this agrees well with the experiments of Gore …

An unexpected conclusion may be deduced from this idea. As all electrolytes in extreme dilution are completely active, then the weak acids must increase in strength with dilution, and approach the strength of the strongest acids. This was soon afterwards shown by Ostwald to agree with experiments.
— Svante August Arrhenius (1859 – 1927), Nobel Lecture, 1903.

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