_Leipzig, September 18, 1852._ “My dear Marie, the very question which has brought me here is surrounded with very great difficulties.... I have only studied one tartar thoroughly since I have been here; it comes from Naples and has been refined once. It contains racemic acid, but in such infinitesimal proportions that it can only be detected by the most delicate process. It is only by manufacture on a very large scale that a certain quantity could be prepared. But I must tell you that the first operation undergone by this tartar must have deprived it almost entirely of racemic acid. Fortunately M. Fikentscher is a most enlightened man, he perfectly understands the importance of this acid and he is prepared to follow most minutely the indications that I shall give him in order to obtain this singular substance in quantities such that it can again be easily turned into commercial use. I can already conceive the history of this product. M. Kestner must have had at his disposal in 1820 some Neapolitan tartars, as indeed he said he had, and he must have operated on crude tartar. That is the whole secret.... But is it certain that almost the whole of the acid is lost in the first manufacture undergone by tartar? I believe it is. But it must be proved. There are at Trieste and at Venice two tartar refineries of which I have the addresses. I also have letters of introduction. I shall examine there (if I find a laboratory) the residual products, and I shall make minute inquiries respecting the places the tartars used in those two cities come from. Finally, I shall procure a few kilogrammes, which I shall carefully study when I get back to France....” _Freiberg, September 23, 1852._ “I arrived on the evening of the 21st at Dresden, and I had to wait until eleven the next morning to have my passport _visé_, so I could not start for Freiberg before seven p.m. I took advantage of that day to visit the capital of Saxony, and I can assure you that I saw some admirable things. There is a most beautiful museum containing pictures by the first masters of every school. I spent over four hours in the galleries, noting on my catalogue the pictures I most enjoyed. Those I liked I marked with a cross; but I soon put two, three crosses, according to the degree of my enthusiasm. I even went as far as four. “I also visited what they call the green vault room, an absolutely unique collection of works of art, gems, jewels ... then some churches, avenues, admirable bridges across the Elbe....