In these early attempts Keats again ventures some way, but not yet far, in the direction of breaking the fetters of the regular couplet. He runs his sentences freely enough through a succession of lines, but nine times out of ten with some kind of pause as well as emphasis on the rime-word. He deals freely in double endings, and occasionally, but not often (oftenest in the epistle to George) breaks the run of a line with a full stop in or near the middle. He is in like manner timid and sparing as yet in the use, to which a little later he was to give rein so fully, of Elizabethan word-forms, or forms modelled for himself on Elizabethan usage. Somewhat more free and adventurous alike in metre and in diction are the two poems, _Sleep and Poetry_ and '_I stood tip-toe_,' which Keats wrote after he came back to London in the autumn. These are the things which, together with two or three of the sonnets, give its real distinction and high promise to the volume. Both in substance and intention they are preludes merely, but preludes of genius, and, although marked by many immaturities, as interesting and attractive perhaps as anything which has ever been written by a poet of the same age about his art and his aspirations. In them the ardent novice communes intently with himself on his own hopes and ambitions. Possessed by the thrilling sense that everything in earth and air is full, as it were, of poetry in solution, he has as yet no clearness as to the forms and modes in which these suspended elements will crystallize for him. In _Sleep and Poetry_ he tries to get into shape his conceptions of the end and aim of poetical endeavour, conjures up the difficulties of his task, counts over the new achievement and growing promise of the time in which he lives, and gives thanks for the encouragement by which he has been personally sustained. In '_I stood tip-toe_' he runs over the stock of nature-images which are his own private and peculiar delight, traces in various phases and aspects of nature a symbolic affinity, or spiritual identity, with various forms and kinds of poetry; tells how such a strain of verse will call up such and such a range of nature images, and conversely how this or that group of outdoor delights will inspire this or that mood of poetic invention; and finally goes on to speculate on the moods which first inspired some of the Grecian tales he loves best, and above all the tale of Endymion and Cynthia, the beneficent wonders of whose bridal night he hopes himself one day to retell.