I was much glad of your letter, and will be thankful for a repetition. I understand better about your not coming.
     [118] I have regularly set up shop now above the wash-house at the gate, in a garret. I have an old door set    on two barrels, and two chairs, of which one is safe, and a skylight above, which will slide up and down. On the door (or table), there is a lot of bowls, jugs, plates, jam pigs, etc., containing water, salt, soda,   sulphuric acid, blue vitriol, plumbago ore; also broken glass, iron, and copper wire, copper and zinc plate, bees'   wax, sealing wax, clay, rosin, charcoal, a lens, a Smee's Galvanic apparatus, and a countless variety of little  beetles, spiders, and wood lice, which fall into the different liquids and poison themselves. I intend to get up some   more galvanism in jam pigs; but I must first copper the interiors of the pigs, so I am experimenting on the best   methods of electrotyping. So I am making copper seals with the device of a beetle. First, I thought a beetle was a   good conductor, so I embedded one in wax (not at all cruel, because I slew him in boiling water in which he never   kicked), leaving his back out; but he would not do. Then I took a cast of him in sealing wax, and pressed wax into    the hollow, and black-leaded it with a brush; but neither would that do. So at last I took my fingers and rubbed it,  which I find the best way to use the black lead. Then it coppered famously. I melt out the wax with the lens, that    being the cleanest way of getting a strong heat, so I do most things with it that need heat. To-day I astonished the  natives as follows. I took a crystal of blue vitriol and put the lens to it, and so drove off the water, leaving a white    powder. Then I did the same to some washing soda, and mixed the two white powders together; and made a  small native spit on them, which turned them green by a mutual exchange, thus:—1. Sulphate of copper and  carbonate of soda. 2. Sulphate of soda and carbonate of copper (blue or green).

 With regard to electro-magnetism you may tell Bob that I have not begun the machine he speaks of, being  occupied with better plans, one of which is rather down cast, however, because the machine when tried    went a bit and stuck; and I did not find out the impediment till I had dreamt over it properly, which I consider the   best mode of resolving difficulties of a particular kind, which may be found out by thought, or especially by the   laws of association. Thus, you are going along the road with a key in your pocket. You hear a clink behind you,  but do not look round, thinking it is nothing particular; when you get home the key is gone; so you dream it all  over, and though you have forgotten everything else, you remember the look of the place, but do not remember  the locality (that is, as thus, "Near a large thistle on the left side of the road"—nowhere in particular, but so that it  can be found). Next day comes a woman from the peats who has found the key in a corresponding place. This is   not "believing in dreams," for the dream did not point out the place by the general locality, but by the lie of the     ground.

Please to write and tell how Academy matters go, if they are coming to a head. I am reading Herodotus, Euterpe,    having taken the turn; that is to say, that sometimes I can do props, read diff. and Int. Calc., Poisson, Hamilton's   dissertations, etc. Off, then I take back to experiments, history of what you may call it, make up leeway in the   newspapers, read Herodotus, and draw the figures of the curves above. O deary, 11 P.M! Hoping to see you   before October. . . . I defer till to-morrow.

July 6. To-day I have set on to the coppering of the jam pig which I polished yesterday.

 I have stuck in the wires better than ever, and it is going on at a great rate, being a rainy day, and the skylight shut   and a smell of Hydrogen gas. I have left it for an hour to read Poisson, as I am pleased with him to-day. [120]   Sometimes I do not like him, because he pretends to give information as to calculations of sorts, whereas he only   tells how it might be done if you were allowed an infinite time to do it in, as well as patience. Of course he never   stoops to give a particular example or even class of them. He tells lies about the way people make barometers,   etc.