It's long, but includes some interesting details, such as that Nieto off-handedly refers to Rashi letters as משקיט (see here), and also he asks Unger to write him back in Latin, because he can't read the Ashkenazic Hebrew script! Also interesting is that he notes that he had not been aware that the book חזוק אמונה was written by a Karaite. Strangely, rather than get angry and retort !שקר וכזב to Unger, he accepts this interesting fact. Hm.
“Greatest of Sages, Chief among Preachers, Ornament of Saints, My Master, Distinguished One and Friend, the Great Sage who is adorned with all manner of wisdom and prudence, the exalted, honoured, and distinguished Christian Theophilus Unger, Peace, from one who proffers peace.More Hebrew correspondence between Christian Theophile Unger and Jewish scholars can be read here, published by Shadal in the 3rd volume of Ignaz Blumenfeld's אוצר נחמד. See also Steinschneider on Unger.
“I have received a letter some days ago from your exalted distinguished honour, and it revived my spirit when I saw that cognizance had been taken of me, and that I had found grace in the sight of a man possessing wisdom and a man of accomplished understanding, and behold I am ready to answer the questions in his gracious epistle in the order he has put them as is his desire; and also to serve him, and to minister unto him according to all the Master may command.
“At first I will say I have neither seen nor heard of a work by Jacob son of Amram in any language, nor of the book Gate of Truth. The Haham Rabbi Menasseh ben Israel died and was buried in Amsterdam, and an old man told me that he expired in the year 1655 or 1656 according to your calculation, but I do not know anything about his books in manuscript. R. Isaac Abendana was not a physician, and I do not know the year he died, and in my time I have neither heard of nor seen the book Faith Strengthened in Spanish, neither in manuscript nor printed. Neither he nor his brother had children. The Haham, Rabbi Jacob, mentioned previously, translated the Cuzary into Spanish with a slight commentary, and it is one which I have sent among the books to your exalted distinguished honour; he was Rabbi in this holy congregation many years, and died on Tishri 3, 5456 Anno Mundi. Before him Rabbi Joshua da Silva was Haham; he died on the 17th of yar 5439, and was the author of a book of sermons in Spanish on the thirteen articles of faith. It is a charming book, and I searched for it, and could not find it, and therefore could not send it; but if I find grace in your sight, my Master, and you return me an answer, I will [again] search for it and send it. After the Haham Rabbi Jacob, as mentioned above, the Haham Rabbi Solomon Ayllon of Salónica was received here as Rab; he guided the Congregation eleven years, and from here he went to Amsterdam in the year 5460, and was received as Rab, and he is still there. After him, I received a call from London from the City of my habitation, Leghorn, where I was Dayan and Preacher of the Congregation and Physician, and came here at the end of Elul 5461; and the city of my birth is Venice. And here I have printed four books, one in Italian, Pascallogia [sic], which I composed in Leghorn in the year 5453, that is 1693, and published here in the year 1702. Although Colonia is printed on the title-page, it is not correct, as I was forced to state so from fear that the Christians in Italy would not receive it: Ratione Autlioris et Urbis ab eis Hereticam appellatam. Afterward I printed a book in Spanish, entitled Divine Providence, in the year 5464. In the year 5474 I printed the book Matteh Dan in the holy tongue, and translated it into Spanish; and sought for a skilled mechanic to cast type of the holy tongue, and also משקיט or Rashi type, and now they are in my possession. I also printed a calendar in Spanish, from the year 5470 until the year 5550 inclusive, but my name is not inscribed on it because at that time I was very much troubled with communal matters, and there were a few errors in it, and I had no opportunity to correct them. If Providence grants me life, it is possible that in the coming winter I will print another calendar up to the year 5511,and there I will correct the errors. Some time ago I heard that the author of the book Faith Strengthened was a Karaite. What your highness wrote about this was quite new to me, and I was as pleased as one who finds a great treasure, and in order that I should not forget it I have put the note at the beginning of his book. I also would inform your exalted and distinguished honour that the Haham Rabbi Jacob Fidanque, his memory be for a blessing, died in the month of Heshvan 5462. I was here during his illness and visited him, and buried him and delivered a funeral oration. His son died on the 4th day of Elul 5469, and he only composed the books known to you. Rabbi David Pardo died in Surinam in America, nearly three years ago, and he only composed what your honour knows. The Haham Rabbi Phoebus is living and well: long may he live. There is no tombstone on the grave of Isaac Abendana, and I know nothing about our teacher, Rabbi David Mungon, nor his book. I have sent a letter to the Haham, Rabbi Moses Hagiz, to Embden, the place where he has resided the past year, but I have not yet received his reply, as he is ill in consequence of the climate of the country not agreeing with him; when it arrives I will forward it immediately.
I would request my master to write to me in Latin, in plain Roman letters, as I am unable to read the Ashkenazi Hebrew script; for this I most humbly apologise to my master, and I will also reply in the Latin tongue to your exalted distinguished honour.
“Yesterday I handed the Secretary of the Envoy of the King of Poland (May his Glory be exalted), these books—
The Cuzari in Spanish.
Matten Dan Vecuzari Chelek Sheni.
De La Divina Providencia.
In this book I have not inscribed my name
openly on account of the squabbles of a minority of the Yehidim of the Holy Congregation with me; but if your Highness will look at the letters that the typesetters use to index the printed matter he will find under A vel B, from leaf 1 up to leaf 53, Sr H.H.R. David Netto [sic] Rab del K.K. de Londres.
“I am also sending as a gift an almanac I have written, as described above. I will implore of God the Creator of Heaven and Earth to prolong his days in goodness and his years in pleasantness, such is the soul’s [desire] of his servant and attendant seeking his peace and welfare here in London. Tamuz 27, 5479.
A final thought: it's a great deal of fun to see how scholars got on in time's past. Today, when you're researching a topic and want to reach out beyond your immediate circle you can email your queries, or you can reach out on Listservs and message boards being as private and as public as you want. In 1915 Israel Solomons sent an observation and a questions that were clearly part of the preparation of the paper from which the above translation is drawn to the periodical Notes & Queries. Here they are: