36 



I. GUARESCHI 



eraporter; je vous l'aurais offert de bon cceur. Dans tous les cas, chose remise n'est pas 

 perdile et je vous prouverai par mon empresseraent à vous ètre utile, qne je suis digne de 

 votre amitié. 



" Adieu, mon cher ami ; revoyez votre belle contrée, votre beau ciel, répandez la science 

 que vous possédez, c'est le moyen le plus sur d'arriver <à des résultats utiles pour l'humanité. 

 Nous corresponderons et nous saurons nous entendre. 



" Votre affectionné ami 

 " Peltibr. 



" Toute la famille vous souhaite un bon voyage, une bonne santé et la direction des sciences 

 à Naples „. . 



Melloni e Faraday. 



Melloni era in ottime relazioni col Faraday; il grande fisico inglese aveva più 

 di tutti i suoi colleghi contribuito a far conferire la medaglia Kumford al Melloni 

 per le sue ricerche sul calore, nel 1835. 



Tra le carte del Melloni ho trovato una lunghissima lettera del Faraday, del 

 31 luglio 1854, scritta con carattere molto fitto; alcune parole sono quasi illeggibili. 



Questa lettera inedita, giunse a quanto pare dopo la morte del Melloni, o forse 

 nei giorni della sua malattia. 



È certamente l'ultima lettera che il Faraday scrisse al Melloni: 



My dear Melloni, 



Royal Institutions, London. 31 july 1854. 



I bave three letters of yours unanswered tbe two last of the dates of the l 5t and the 12 th 

 instant. I have been unable to answer tbem before, because the beginning of the month I was 

 in the country, and I returned from it only to place myself under the surgeon's hands : and 

 since then have been unable to write or work : I am now getting better but ain stili in his care. 



When I rcceived your last letter, I had no need to repeat your experiments ; for they were 

 ali perfectly familiar to me, as far as I could judge by yqur description, and are necessary 

 consequences of the theory of static induction, whieh* I published in the Philosophical Trans- 

 actions 17 years ago. Stili I should have sent your letter to me to the Royal Society as you 

 requested, if it had been open : but its sittings were closed on the 15 june, a month before 

 your letter was written, -so that I was unable to fulfil your desires in that respect. 



Your difficulties present no difficulties to me, neither do I remember clearly the error or 

 illusion into which we have ali fallen and which you say is continued in ali the books. The 

 fact is I have interpreted induction according to' my own views in the last 18 years and 

 have not carefully analyzed the words of recent treatises, but I do not remember that the 

 statement of Pouillet or De La Rive contradict my notions. As my views though given at length 

 in the Philosoph. Trans, in the years 1837 and 1838 in the series XI, XII, XIII and XIV of my 

 Experimental Researches, have not been published either in French or Italian, they probably have 

 never come under your notice : I endeavoured to send English copies of thera at the time, 

 through the Royal Society, but very likely they never reached you: so I am about to give 

 you a brief summary of tbem, referring to the members of the paragraphs in the Exp. Re- 

 searches, that you may, if you desire it, look at- the originai matter. 



But first let me remind you, that I do not as yet know the nature of your Electrotneter 

 and therefore may have misunderstood your statement altogether; though as regards the simple 

 results with (fig. 1), shaded or not. I do not think that likely, for they are precisely the 

 same as my own old ones. 



I profess to know nothing of the existence of either one or two electric fluids, or of the 

 nature of the electric power, exerted either in a P, or an N direction (1298 note 1667), but 



