When he began to investigate for himself, it could not have been easy to separate his own work from that which he was expected to do for his master. Hence no small danger of misunderstandings and jealousies; and some of these ugly attendants on rising fame did actually throw their black shadows over the intercourse between the older and the younger man of genius. In these earlier years, however, all appears to have been bright; and the following letter, written from Rome in October 1818, will give a good idea of the assistant's miscellaneous duties, and of the pleasant feelings of Davy towards him. It may be added that in another letter he is requested to send some dozens of "flies with pale bodies" to Florence, for Sir Humphry loved fly-fishing as well as philosophy. "TO MR. FARADAY. "I received the note you were so good as to address to me at Venice; and by a letter from Mr. Hatchett I find that you have found the parallax of Mr. West's Sirius, and that, as I expected, he is mistaken. "If when you write to me you will give the 3 per cents. and _long annuities_, it will be enough. "I will thank you to put the enclosed letters into the post, except those for Messrs. Morland and Messrs. Drummond, which perhaps you will be good enough to deliver. "Mr. Hatchett's letter contained praises of you which were very gratifying to me; and pray believe me there is no one more interested in your success and welfare than your sincere well-wisher and friend, "H. DAVY. "ROME." It must not be supposed, however, that he had any astronomical duties, for the parallax he had found was not that of the Dog-star, but of a reputed new metal, Sirium, which was resolved in Faraday's hands into iron, nickel, and sulphur. But the impostor was not to be put down so easily, for he turned up again under the _alias_ of Vestium; but again he was unable to escape the vigilant eye of the young detective, for one known substance after another was removed from it; and then, says Faraday, "my Vestium entirely disappeared."