MS not found; retranslated from a translation into Italian printed
    in Guiseppe A. F. G. Eandi, Memorie istoriche intorno gli studi
    del padre Giambatista Beccaria delle Scuole Pie professore
    di fisica sperimentale nella R. Università di Torino ec.
    (Torino, 1783), pp. 146-8.
  
  
    London, May 29. 1766.
  
  
    It gives me pleasure to transmit to you
    herewith the thanks of our society for your most ingenious paper on
    electrical matters, and permit me to add to them my own
    [thanks].
    In conformity with your wishes, it had been
    shown to me before it was presented to the society, and I
    recommended it as well deserving the society’s attention.
    Before it is printed in the Transactions
    I should like to know whether there is not some mistake in that
    part of the table where you say:
   
  
    If these are not writing mistakes, but agree
    with facts, I should like to know what circumstances in the
    experiments you think may account for [the fact] that in the
    reciprocal rubbing of those substances one of them does not supply
    the same quantity as the other receives.
    I ought to have thanked you before now for the
    favor you did to me some time ago by sending me your books on
    electrical matters, and for your mentioning me honorably in them.
    Rest assured that I have read no other work on this subject that
    has given me so much pleasure. A new edition of my writings, with
    many additions, is being printed here; when it is finished I shall
    beg you to accept a copy. A small paper on meteorology which was
    read to the society some time ago, but not yet printed in the
    Transactions, is appended to it.
    Since I came back here from America in 1765 I
    have found only one new thing about electricity: this is that, if a
    spark is sent into the dark around bodies which imbibe light
    (as I believe I must express myself), these bodies shine briskly
    for a few minutes thereafter. It is not necessary for electric fire
    to go through the body; a spark that passes at a two- or three-inch
    distance is sufficient. I suppose that Bologna stone may be used
    for this experiment. Here we use an artificial compound of calcined
    oyster shells, burned in a crucible with sulphur. A spark of your
    fulminating table would give a long lasting light. I am
    sending you a small piece of wood covered with a little of this
    compound, which was given me, and made by Mr. Canton, a member of
    our society. The discoverer of this effect of electricity was Mr.
    Lane, who also has devised an elegant method, by means of a screw,
    to give exactly equal shocks of a certain determined strength for
    medical objects, as the bottle will always discharge when it has
    received the quantity of fire that will hit at the distance
    determined by the screw.
    I am pleased to hear that you read English,
    although you do not write it. I am in the same case with Italian.
    Hence we can correspond, if this pleases you, more easily if each
    of us writes his own language. I shall thus more often take the
    opportunity of expressing to you through my letters the great
    esteem, and the respect, with which I am, Reverend Sir, Your most
    obedient and most humble servant.