Faraday to Lord Ashley¹   28 June 1842

Royal Institution, 28 June 1842.

My Lord,

Though it gives me great pleasure to do anything your Lordship may desire, yet I cannot but regret the kind of report I have to make on the flour left with me; I console myself with the hope that it may work good in your Lordship’s hands.

The specimens consisted of powder and lumps. Part of the powder is old flour, and I cannot judge sufficient to say whether it is good or bad. Some of the lumps are portions of aggregated flour; they are brownish and hard, and appear to result from flour wetted: whether they are wheaten flour or not, I cannot say, but they are the best parts of the specimen, for they contain no extra earthy matter. Other lumps are much whiter, and are better looking, but are principally made up of clay. I return four bottles, and will thus account for them:- your Lordship sent me 252 grains of mixture. Bottle No. 1 contains 29 grains of the best looking white lumps, principally clay, which I picked out as a specimen. Bottle No. 2 contains 33 grains of the hardened lumps, which I presume is flour that has been wetted; the other 190 grains I pulverized in a mortar, breaking up all the lumps, and producing an uniform mixture; a part of it is in bottle No. 3. Of this I took 50 grains and analysed it; it gave me 9½ grains of white, earthy matter, in fact, white clay, which had been added to the flour, and this clay is now in bottle No. 4.

So, of the powder or flour in bottle 3, 19 per cent. is clay; and if I had left in all the other lumps, so as to have an average of the whole 252 grains, the clay would have been 24 per cent. or nearly a fourth of the whole.

For a comparative experiment, I took 50 grains of good flour from a jar in the laboratory; it gave me the usual fusible ash of phosphats silica and alkali, amounting to 0.3 of a grain, or 0.6 of a grain per cent., being 1/166 part instead of ¼.

I should have liked to preserve the specimens, but thought your Lordship might desire to have them, and therefore send them sealed up in paper².

I am &c. | (signed) M. Faraday.

The Right Hon. Lord Ashley, M.P. | &c. &c. &c.