Faraday to Benjamin Abbott   9 February 1816

<qr>R.I Friday Eveg 1816 Dear Abbott

Be not offended that I turn to write you a letter because I feel a disinclination to do anything else, but rather accept it as a proof that conversation with you has more power with me than any other relaxation from business. - business I say, and I believe it is the first time for many years that I have applied it to my own occupations, but at present they actually deserve the name; and you must not think me in a laughing mood, but in earnest. It is now 9 o clk P.M., and I have just left the Laboratory and the preparations for tomorrow’s two Lectures. Our double course makes me work enough, and to them add the attendance required by Sir H.<_> in his researches, and then if you compare my time with what is to be done in it you will excuse the slow progress of our correspondence on my side - Understand me I am not complaining the more I have to do the more I learn but I wish to avoid all suspicions on your side that I am lazy. - Suspicions by the bye which a moments reflection convinces me can never exist[.] Mr. Wheeler¹ attends both our courses of chemical lectures very closely and I perceive with surprise that that singularly acetous physiognomy which I first saw at the Surrey Institution² belongs to him naturally and that instead of being caused by the dread of an attending company he wears it at all times - But it is time I should reperuse your letter & answer it by something more allied to it than this unconnected irregular coarse material[.]

I thank you for the promise you give me of taking up the subject I proposed and expect much information on it. If with your original observations you sometimes give me the ideas of others as concuring with or opposing your own and if you can point out to me such a course or reading or study as might bring me a little acquainted with the subject and can direct me to such books as you know to be good it will enhance the value of your communications[.]

Having thus noticed what comes before your “First” then I will answer to that and say that I have seen the combustion of the taper in the flame of Alcohol. - but before I go farther I will enter a little more minutely into the subject which I fear I badly explained to you[.] Newton I believe defines flame to be red hot vapours³ but perhaps ignited vapours because all flame is not red would have been better this definition is I think a good one and by flame I understand nothing more than what is expressed in it and of course I do not consider vapour not ignited or not emitting light as flame[.] It must however be evident to you that in every case of combustion where flame is produced from a pure combustible, vapour in both those states is present i.e. ignited vapour & vapour not ignited[.] In the flame of a candle for instance there is a small dull halo round the wick within the flame & this I do not consider as a part of the flame but merely the vaporized tallow which not being luminous must of course diminish the effect of that part of the whole flame and make it appear inferior in power to the superior parts where the whole body is luminous[.] Now in this central and nonignited space I do not think any thing will burn because no oxygene is there present for if it were the vapour would burn & be luminous but above this part and where the flame appears uniform & luminous throughout, there I say that oxygene exists even in the centre of the flame and if any body is intruded into that part having a stronger affinity for oxygene than the hydrogen & charcoal of the tallow it will burn and its flame will be seen within the flame of the candle.- It is the same with Alcohol but in the large flames we can make with it the circumstances are more distinct[.] I made a little experiment this evening thus[.] Into a small wedgewoods basin (diameter 2 inches) I poured Alcohol having previously fixed a taper of an inch in length in the middle of it the alcohol was level with the edges & the bottom of the flame of the taper when it was lighted was about 1/2 inch above the alcohol. I lighted the taper and the alcohol and then placed a long [MS torn] the dish to preserve the flames from the interference of chance [MS torn] in the air the flame of the alcohol was well formed and very steady the unignited part was very considerable & perfectly distinct it extended above the top of the taper the flame of the taper did not go out on lighting the alcohol but appeared to separate from it and hang over it and shone very bright in the upper part of the alcohol flame commencing immediately from the unignited vapour. You will instantly conceive the explanation I give of this phenomenon namely that the space in the center of the flame & immediately over the alcohol is pure vapour that as the air mixes with the vapour at the sides entering itself farther & farther as it rises higher so in proportion flame is formed that where the flame was permanent throughout then oxygen was present even in the center that the volatile parts of the taper will not burn in the pure vapours of Alcohol but did in the flame & then formed its flame within that of the alcohol &c and I am not aware of any objections that may arise in your mind respecting them - If a chance breath distorted the flame then as the lower & superficial part approached in its waverings the wick of the taper it lighted up & its flame appeared though still within that of the alcohol and in such cases I supposed that the wick of the taper had come within the oxygenated part of the alcoholic vapour.

Returning for a moment to my first instance of a candle the only part of it where I can suppose any thing like combustion at surfaces to take place is at the lowest part of the flame there you will perceive a very faint blue light more marked at the edges than at the entering parts because there we see more of it at once but the light is at best very little[.] Even This however evidently results from an intermixture of the vapour with the air (but the two have not penetrated each other far) and upon close examination you will find that even this faint combustible does not commence at the wick but at a small distance from it and that when the vapour of the tallow and the common air are merely in contact & have not had time to mix there is no flame[.] I shall leave this subject with Sir H.D.’s theory of blowing out a candle which operation has never yet been satisfactorily explained - He says that as inflammable gases will only burn in certain proportion with air to extinguish a combustion we must make the mixture pass from these proportions this may be done either by adding more of the inflammable or more of the air by adding more of the inflammable the oxygene is diluted by adding more of the air the inflammable is diluted this last is the case in blowing out a candle the vapour of the tallow is diluted with so much common air as to be uninflammable & if so the fl<<ame the>>n exists no longer.

Having unconsciously run on so fast & so far I shall cut off the rest of your letter with brief notices - I have no hand in the Catalogue - I am writing a second Lecture so that the book is engaged at this moment but is at your service⁴ - Is not time a succession of events - by an ignorant person you do not mean a blockhead. If I were to ask you what Thoan was and should afterwards tell you by that term I understand a succession of events would you not say that my Thoan and the common word time had the same meaning.- Can you take tea with me on Monday.- our two Lectures on Saturday allow me no spare time at the end of the week and I have forgot your free days.

I heard from Robert the other day that Miss Abbott had a nasty cold I hope it is much better and more I hope it has no connection with “waddling” “night & morning” Your own words Ben.

Remember me to our friends & believe me | Ever Yours

| M. Faraday

Feby. 9th. I believe

Address: Mr. B. Abbott | Long Lane | Bermondsey