From Boswell's Life of Johnson, Vol. III, P.321:

We went to the drawing room, where was a considerable increase of company. Several of us got round Dr. Johnson, and complained that he would not give us an exact catalogue of his works, that there might be a complete edition. He smiled, and evaded our entreaties. That he. intended to do it I have no doubt, because I have heard him say so; and I have in my possession an imperfect list, fairly written out, which he entitles Historia Studiorum. I once got from one of his friends a list which there was pretty good reason to suppose was accurate, for it was written down in his presence by this friend, who enumerated each article aloud, and had some of them mentioned to him by Mr. Levett, in concert with whom it was made out; and Johnson, who heard all this, did not contradict it. But when I showed a copy of this list to him, and mentioned the evidence for its exactness, he laughed and said, " I was willing to let them go on as they pleased, and never interfered." Upon which I read it to him, article by article, and got him positively to own or refuse; and then, having obtained certainty so far, I got some other articles confirmed by him directly, and afterwards, from time to time, made additions under his sanction.