Banks, then President of the Royal Society. Naturally 1812. enough, "no answer" was the reply left with the ET.20-21. porter.'

On Sunday, July 12, 1812, three months before his apprenticeship ended, he began to write to Benjamin Abbott, who was a year and a half younger than his friend; but Abbott had been at good schools and was well educated, and hence Faraday regarded him as the possessor of a knowledge far beyond his own. Throughout all his correspondence this deference to his friend's superior school knowledge is always to be seen. These letters Mr. Abbott has most fortunately kept, thinking that at some future time they would be invaluable records of his friend's youth. They show his thoughts when he was 'giving up trade and taking to science,' during the period when the greatest change in the course of his life took place. The first eight were written between July 12 and October 1 in this year, whilst he was still an apprentice in Blandford Street.

They possess an interest almost beyond any other letters which Faraday afterwards wrote. It is difficult to believe that they were written by one who had been a newspaper boy and who was still a bookbinder's apprentice, not yet twenty-one years of age, and whose only education had been the rudiments of reading, writing, and arithmetic.

Had they been written by a highly educated gentleman, they would have been remarkable for the energy, correctness, and fluency of their style, and for the courtesy, kindness, candour, deference, and even humility, of the thoughts they contain.

1812.

ÆT.20-21.

FARADAY'S FIRST LETTER TO BENJAMIN ABBOTT.

'Dear A, Ceremony is useless in many cases, and sometimes impertinent; now between you and me it may not be the last, yet I conceive it is the first: therefore I have banished it at this time. But first let me wish you well, and then I will proceed on to the subject of this letter. Make my respects, too, if you please, to Mr. and Mrs. A., and also to your brother and sister.

'I was lately engaged in conversation with a gentleman who appeared to have a very extensive correspondence for within the space of half an hour he drew observations from two letters that he had received not a fortnight before-one was from Sicily and the other from France. After a while I adverted to his correspondence, and observed that it must be very interesting and a source of great pleasure to himself. He immediately affirmed, with great enthusiasm, that it was one of the purest enjoyments of his life (observe, he, like you and your humble servant, is a bachelor). Much more passed on the subject, but I will not waste your time in recapitulating it. However, let me notice, before I cease from praising and recommending epistolary correspondence, that the great Dr. Isaac Watts (great in all the methods respecting the attainment of learning) recommends it as a very effectual method of improving the mind of the person who writes and the person who receives. Not to forget, too, another strong instance in favour of the practice, I will merely call to your mind the correspondence that passed between Lord Chesterfield and his son. In general, I do not approve of the moral tendency of Lord Chesterfield's letters, but I heartily agree with him respecting the utility of a written correspondence. It, like many other

good things, can be made to suffer an abuse, but that is no effectual argument against its good effects.

'On looking back, I find, dear A., that I have filled two pages with very uninteresting matter, and was intending to go on with more, had I not suddenly been stopped by the lower edge of the paper. This circumstance (happily for you, for I should have put you to sleep else) has" called back my wand'ring thoughts;" and I will now give you what I at first intended this letter should be wholly composed of philosophical information and ideas.

I have lately made a few simple galvanic experiments, merely to illustrate to myself the first principles of the science. I was going to Knight's to obtain some nickel, and bethought me that they had malleable zinc. I inquired and bought some-have you seen any yet? The first portion I obtained was in the thinnest pieces possible observe, in a flattened state. It was, they informed me, thin enough for the electric stick, or, as I before called it, De Luc's electric column. I obtained it for the purpose of forming discs, with which and copper to make a little battery. The first I completed contained the immense number of seven pairs of plates!!! and of the immense size of halfpence each!!!!!!

'I, Sir, I my own self, cut out seven discs of the size of halfpennies each! I, Sir, covered them with seven halfpence, and I interposed between, seven, or rather six, pieces of paper soaked in a solution of muriate of soda!!! But laugh no longer, dear A.; rather wonder at the effects this trivial power produced. It was sufficient to produce the decomposition of sulphate

1812.

T. 20-1.

1812.

of magnesia-an effect which extremely surprised me; ET. 20-1. for I did not, could not, have any idea that the agent was competent to the purpose. A thought here struck me; I will tell you. I made the communication between the top and bottom of the pile and the solution. with copper wire. Do you conceive that it was the copper that decomposed the earthy sulphate-that part, I mean, immersed in the solution? That a galvanic effect took place I am sure; for both wires became covered in a short time with bubbles of some gas, and a continued stream of very minute bubbles, appearing like small particles, ran through the solution from the negative wire. My proof that the sulphate was decomposed was, that in about two hours the clear solution became turbid: magnesia was suspended in it.

'Seeing the great effect of this small power, I procured from Knight some plate zinc, or sheet zinc I think they call it, about the thickness of pasteboard; from this I cut out discs, and also obtained some sheet copper, and procured discs of that metal. The discs. were about 14 inch in diameter. These I piled up as a battery, interposing a solution of the muriate of soda by means of flannel discs of the same size. As yet I have only made one trial, and at that time had, I believe, about eighteen or twenty pairs of plates. With this power I have decomposed the sulphate of magnesia, the sulphate of copper, the acetate of lead, and I at first thought also water, but my conclusions in that respect were perhaps too hastily made.

'I inserted the wires into a portion of water that I took out of the cistern, and of course, in a short time, strong action commenced. A dense-I may really say

dense-white cloud of matter descended from the 1812. positive wire, and bubbles rose rapidly and in quick Er. 20-1. succession from the negative wire; but after a time I perceived that the action slackened: the white cloud was scarcely perceptible at the wire, though by the former action the lower part of the solution was perfectly opaque and the bubbles nearly ceased. I thought that the action of the battery was exhausted; but in philosophy we do not admit suppositions; and therefore, to prove whether the battery was inert, or whether any principle in the water was exhausted, I substituted a fresh portion of water for that which had been galvanised. Then the action commenced again, and went on as at first. The white precipitate again appeared, and bubbles rose as before; but after a while it ceased, as in the first instance.

I make no affirmative conclusion from these phenomena, but this I presume, that the water was not decomposed. Our water comes through iron pipes, and is retained in a leaden cistern. I have also ascertained that it holds a small portion of muriatic acid, and have no doubt that it contains carbonic acid. Now, do you think that any part of the lead or iron (the lead I should rather fancy) is held in solution by the muriatic or carbonic acid, and that the bubbles are formed by the precipitation of the metal, whilst the acid-what a blunder! I mean that the bubbles are formed by the escape of the acid and the precipitate-is the metallic oxide? Explain this circumstance to me—will you?— either by your pen or your tongue. Another phenomenon I observed was this: on separating the discs from each other, I found that some of the zinc discs had got a coating-a very superficial one in some