In the advanced collection of to-day there is no wavering over the used and the unused question. A lot of ink has been spilt in the controversies over the comparative interest, importance, or other claim of these two general conditions of postage-stamps. To-day both unused and used stamps are necessary to the study of stamps. A specialised collection containing only unused specimens would indeed be an "ill-roasted egg," and would fail to show the history of the stamps during their currency. The unused stamps show the pristine condition of the varying shades of successive printings; the used ones enable the collector to place those successive shades in their correct sequence, even to show for what purpose special printings were required. The most evidential items in a stamp collection are often the used copies which have been preserved on the entire original envelope, a fact which gives to the stamp used on the envelope a special value not always to be gauged by the catalogue quotation for an ordinary used copy. A Penny Black stamp of Great Britain should be worth at least two to three times "catalogue" if on the entire original; but if the original had been used on May 6, 1840 (the first day authorised for its use), the envelope with stamp would acquire an exceptional interest out of all proportion to "catalogue." In a specialised price list before me at this moment it is priced at £10, less 25 per cent., for the entire letter; one used on the following Sunday, May 10th, is priced at £15.[13] The Rev. G. C. B. Madden, of Armitage Bridge, had a copy on a letter of May 5th, but the _stamp_ was not cancelled. The cover bears the stamp and the indication-- "_Paid Penny Postage_, "Miss Jones, "Addington Square, "Camberwell." and the enclosure is as follows:-- "BROMPTON PLACE, "_May 5, 1840_. "MY DEAR FLORAL FRIEND,--To make you stare I send you a Queen's Head, the day before it is in Penny Circulation. To-morrow it will be obliterated by a Post Office Stamp. What a pity that they should make Victoria Gummy like an old woman, without teeth as I am. I write this without spectacles, therefore will strain my ninety-and-one eyes no longer than in saying I hope you are All well at Home. "Yours "Gratefully, "JOHN ALEXANDER." The cancellation may also be a factor in the relative scarcity of a used specimen. Coloured postmarks often have some special significance or may be merely accidental applications of the "chops" to the wrong inking pad. In the price list already mentioned I find the Penny Black quoted with the various coloured Maltese cross postmarks (ordinary used copies, not on "entire") as follows:--red 8d., black 9d., blue 60s., violet 40s., marone 4s., brown 5s., orange 7s. 6d., yellow 15s., vermilion 4s., carmine 2s. 6d. [Illustration: THE ONE PENNY "POST OFFICE" MAURITIUS ON THE ORIGINAL LETTER-COVER.