"The Jews of Constantinople, and indeed most of the cities in Turkey, are Spanish Jews; and to the present day speak a language which with great propriety may be denominated the Jewish Spanish. I formerly entertained an idea, that perhaps they had adopted the Turkish as the language of their families, and of their written intercourse with each other: this however is not the case, for in every quarter of Asiatic and European Turkey, where the Spanish Jews are to be found, the Jewish Spanish is the language of their family circles and of their written correspondence. This language of their’s is said to be spoken and written with the greatest purity in Salonica, (the ancient Thessalonica,) where their numbers amount to about 10,000 souls. Their numbers in and about Constantinople are very considerable, but cannot be exactly ascertained, from causes over which a traveller has no controul (sic). However, I have heard some of the most intelligent Jews here estimate them at between 60 and 70,000 souls. They reckon about 8000 more in Smyrna [Izmir], 4000 in Adrianople [Edirne], 3000 in Gallipoli, 3000 in Brusa [Bursa], 7000 in Jenichere [?], 100 families at the Dardanelles, and so further in other towns of minor note throughout Turkey."
Source: American Bible Society, Annual report of the American Bible Society. 1821. Page 182.