5 Even Mrs. Priestley, who might be forgiven for regarding the destroyers of her household gods with some asperity, contents herself, in writing to Mrs. Barbauld, with the sarcasm that the Birmingham people "will scarcely find so many respectable characters, a second time, to make a bonfire of."
6 Experiments and Observations on Different Kinds of Air, vol. ii. p. 31.
7 Experiments and Observations on Different Kinds of Air, vol. ii. pp. 34, 35.
8 Ibid. vol. i. p. 40.
9 Experiments and Observations on Different Kinds of Air, vol. ii. p. 48.
10 Ibid. p. 55.
11 Ibid. p. 60. The italics are Priestley's own.
12 "In all the newspapers and most of the periodical publications I was represented as an unbeliever in Revelation, and no better than an atheist."--Autobiography, Rutt, vol i. p. 124. "On the walls of houses, etc., and especially where I usually went, were to be seen, in large characters, 'MADAN FOR EVER; DAMN PRIESTLEY; NO PRESBYTERIANISM; DAMN THE PRESBYTERIANS,' etc., etc.; and, at one time, I was followed by a number of boys, who left their play, repeating what they had seen on the walls, and shouting out, 'Damn Priestley; damn him, damn him, for ever, for ever,' etc., etc. This was no doubt a lesson which they had been taught by their parents, and what they, I fear, had learned from their superiors."--Appeal to the Public on the Subject of the Riots at Birmingham.
13 First Series. On Some of the Peculiarities of the Christian Religion. Essay I. "Revelation of a Future State."
14 Not only is Priestley at one with Bishop Courtenay in this matter, but with Hartley and Bonnet, both of them stout champions of Christianity. Moreover, Archbishop Whately's essay is little better than an expansion of the first paragraph of Hume's famous essay on the Immortality of the Soul:--"By the mere light of reason it seems difficult to prove the immortality of the soul; the arguments for it are commonly derived either from metaphysical topics, or moral, or physical. But it is in reality the Gospel, and the Gospel alone, that has brought life and immortality to light." It is impossible to imagine that a man of Whately's tastes and acquirements had not read Hume or Hartley, though he refers to neither.
15 Essay on the First Principles of Government, Second edition, 1771.
16 "Utility of Establishments," in Essay on First Principles of Government, 1771.
17 In 1732 Doddridge was cited for teaching without the Bishop's leave, at Northampton.
II
ON THE EDUCATIONAL VALUE OF THE NATURAL HISTORY SCIENCES
[1854]
The subject to which I have to beg your attention during the ensuing hour is "The Relation of Physiological Science to other branches of Knowledge."
Had circumstances permitted of the delivery, in their strict logical order, of that series of discourses of which the present lecture is a member, I should have preceded my friend and colleague Mr. Henfrey, who addressed you on Monday last; but while, for the sake of that order, I must beg you to suppose that this discussion of the Educational bearings of Biology in general does precede that of Special Zoology and Botany, I am rejoiced to be able to take advantage of the light thus already thrown upon the tendency and methods of Physiological Science.
Regarding Physiological Science, then, in its widest sense--as the equivalent of Biology--the Science of Individual Life--we have to consider in succession:
1. Its position and scope as a branch of knowledge.
2. Its value as a means of mental discipline.
3. Its worth as practical information.
And lastly,
4. At what period it may best be made a branch of Education.
Our conclusions on the first of these heads must depend, of course, upon the nature of the subject-matter of Biology; and I think a few preliminary considerations will place before you in a clear light the vast difference which exists between the living bodies with which Physiological science is concerned, and the remainder of the universe;--between the phaenomena of Number and Space, of Physical and of Chemical force, on the one hand, and those of Life on the other.
The mathematician, the physicist, and the chemist contemplate things in a condition of rest; they look upon a state of equilibrium as that to which all bodies normally tend.
The mathematician does not suppose that a quantity will alter, or that a given point in space will change its direction with regard to another point, spontaneously. And it is the same with the physicist. When Newton saw the apple fall, he concluded at once that the act of falling was not the result of any power inherent in the apple, but that it was the result of the action of something else on the apple. In a similar manner, all physical force is regarded as the disturbance of an equilibrium to which things tended before its exertion,--to which they will tend again after its cessation.
The chemist equally regards chemical change in a body as the effect of the action of something external to the body changed. A chemical compound once formed would persist for ever, if no alteration took place in surrounding conditions.
But to the student of Life the aspect of Nature is reversed. Here, incessant, and, so far as we know, spontaneous change is the rule, rest the exception--the anomaly to be accounted for. Living things have no inertia, and tend to no equilibrium.
Permit me, however, to give more force and clearness to these somewhat abstract considerations by an illustration or two.
Imagine a vessel full of water, at the ordinary temperature, in an atmosphere saturated with vapour. The quantity and the figure of that water will not change, so far as we know, for ever.
Suppose a lump of gold be thrown into the vessel--motion and disturbance of figure exactly proportional to the momentum of the gold will take place. But after a time the effects of this disturbance will subside--equilibrium will be restored, and the water will return to its passive state.
Expose the water to cold--it will solidify--and in so doing its particles will arrange themselves in definite crystalline shapes. But once formed, these crystals change no further.
Again, substitute for the lump of gold some substance capable of entering into chemical relations with the water:--say, a mass of that substance which is called "protein"--the substance of flesh:--a very considerable disturbance of equilibrium will take place--all sorts of chemical compositions and decompositions will occur; but in the end, as before, the result will be the resumption of a condition of rest.
Instead of such a mass of dead protein, however, take a particle of living protein--one of those minute microscopic living things which throng our pools, and are known as Infusoria--such a creature, for instance, as an Euglena, and place it in our vessel of water. It is a round mass provided with a long filament, and except in this peculiarity of shape, presents no appreciable physical or chemical difference whereby it might be distinguished from the particle of dead protein.
But the difference in the phaenomena to which it will give rise is immense: in the first place it will develop a vast quantity of physical force--cleaving the water in all directions with considerable rapidity by means of the vibrations of the long filament or cilium.
Nor is the amount of chemical energy which the little creature possesses less striking. It is a perfect laboratory in itself, and it will act and react upon the water and the matters contained therein; converting them into new compounds resembling its own substance, and at the same time giving up portions of its own substance which have become effete.
Furthermore, the Euglena will increase in size; but this increase is by no means unlimited, as the increase of a crystal might be. After it has grown to a certain extent it divides, and each portion assumes the