HARDWICKE'S SCIENCE-GOSSIP. 



283 



live in glass houses should not throw stones ? 

 " Medica " is, I believe, the fern. gend. of " Medicus," 

 and, I also believe, in Latin as well as in English, the 

 pronoun in a general way agrees with the noun. In 

 reply to "Notes on Leprosy," I would call to the 

 writer's remembrance the fact that such a thing has 

 been known in the columns of this journal as one 

 disputant calling another " an antiquated old fossil," 

 " a variety monger ; " and, fearing lest this latter title 

 be applied to me by the writer who seeks to cut 

 down my nomenclature of the disease of leprosy from 

 six species to two, I make my bow, and retire. Yet, 

 I must say, that I think the note on swelling appears, 

 at first sight, to give a wrong impression. It seem to 

 insinuate that swelling is not a symptom of leprosy 

 properly so-called. Whether this be intended or not, 

 of course I cannot say. — Medica. 



The Life of a Shooting Star. — A small body, 

 perhaps as large as a paving-stone or larger, more 

 often perhaps not as large as a marble, is moving 

 round the sun. Just as a mighty planet revolves in 

 an ellipse, so this small object will move round and 

 round in an ellipse, with the sun in the focus. There 

 are, at the present mom.ent, inconceivable myriads of 

 such meteors moving in this manner. They are too 

 small and too distant for our telescopes, and we can 

 never see them except under extraordinary circum- 

 stances. At the time we see the meteor it is usually 

 moving with enormous velocity, so that it often 

 traverses a distance of more than twenty miles in a 

 second of time. Such a velocity is almost impossible 

 near the earth's surface : the resistance of the air 

 would prevent it. Aloft, in the emptiness of space, 

 there is no air to resist the meteor. It may have 

 been moving round and round the sun for thousands, 

 perhaps for millions of years, without let or hindrance ; 

 but the supreme moment arrives, and the meteor 

 perishes in a streak of splendour. In the course of 

 its wanderings the body comes near the earth, and 

 within a few hundred miles of its surface, of course, 

 begins to encounter the upper surface of the 

 atmosphere with which the earth is enclosed. To 

 a body moving with the appalling velocity of a 

 meteor, a plunge into the atmosphere is usually fatal. 

 Even though the upper layers of air are excessively 

 attenuated, yet they suddenly check the velocity, 

 almost as a rifle bullet would be checked when fired 

 into water. As the meteor rushes through the 

 atmosphere the friction of the air warms its surface ; 

 gradually it becomes red-hot, then white-hot, and is 

 finally driven off into vapour with a brilliant light, 

 while we on the earth, one or two hundred miles 

 below, exclaim : " Oh, look ! there is a shooting star." 

 — From " The Story of the Heavens " for November. 



Commercial Botany. — It would be impossible 

 to form any correct idea of what has been attained in 

 the knowledge of plants, useful or otherwise, with- 

 out referring to the results of the principal expeditions 

 which have left our shores for different parts of the 

 world during the present century ; such, for instance, 

 as Ross's Antarctic Expedition, which resulted in 

 " The Botany of the Antarctic Voyage of H.M. Ships 

 ' Erebus ' and ' Terror,' in the years 1839 to 1843," by 

 Dr. (now Sir) J. D. Hooker ; or Captain Reliefs 

 voyage of the 'Herald,' after which appeared " The 

 Botany of H.M.S. ' Herald ' during the years 1S45 to 

 1851," by Berthold Seeman ; or, instill later times, 

 Captain Nares' ' Challenger ' Expedition from 1873 to 

 1876, the botany of which occupies two large volumes, 

 principally the work of Mr. W. B. Hemsley, F. R.S. 

 Not that these expeditions have resulted directly in 

 the introduction of any one useful plant either for 



general culture or commerce, but they have been 

 instrumental in imparting a knowledge of the 

 resources of the several countries visited, and in this 

 way have awakened an interest in them. Important, 

 indeed, as these expeditions have been in elucidating 

 the botany of the world, still more so has been the 

 formation of the several museums in the principal 

 centres of the United Kingdom, for the especial 

 purpose of developing the economic resources of 

 the vegetable, animal and mineral kingdoms, such 

 as the Food Collection, first at South Kensington in 

 1857 and later at Bethnal Green, the Industrial 

 Museum at Edinburgh, and the Museums of Economic 

 Botany at Kew, founded in 1847. These, together 

 with the Royal Botanic Society of London, founded 

 in 1839, and the Pharmaceutical Society of Great 

 Britain, founded in 1841, must always be considered 

 the centres from which knowledge on these points has 

 flowed, and continues to flow. Nor must we forget 

 the several International Exhibitions since 1851, 

 where the vegetable resources of the globe, especially 

 of our colonies, have been prominently brought to 

 the notice of millions of people. Then, in connection 

 with these museums and exhibitions is the literature 

 which emanates from them, such as the handbooks 

 and guides, in which, though published mostly for a 

 few pence, a mass of valuable information is given. 

 We cannot leave this part of the subject without a 

 word of high commendation on the handbooks and 

 catalogues issued by the several colonies at the 

 Colonial and Indian Exhibition of 1886, which should 

 be in the library of every one interested in Economic 

 Botany. — From CasseiPs "New Popular Educator" 

 for November. 



Toads Changing Colour. — Is it a recognised 

 fact that toads will change colour after the fashion of 

 the chameleon ? During the past season I have had 

 three toads in a cucumber frame, two spotted in the 

 ordinary manner and one a deep brown. The two 

 former died. On clearing out the frame to prepare 

 it for wintering plants in, I removed the third for 

 safety, and placed it under an inverted flower-pot on 

 the grass. It was there perhaps half an hour. On 

 lifting the pot to replace the toad in the frame, I found 

 it had changed from brown to a dirty yellowish -green 

 with the usual dark spots. It soon recovered its 

 former brown colour when in the frame. — H. 



NOTICES TO CORRESPONDENTS. 



To Correspondents and Exchangers. — As we now 

 publish Scienck-Gossip earlier than formerly, we cannot un- 

 dertake to insert in the following number any communications 

 which reach us later than the 8th of the previous month. 



To Anonymous Querists. — We must adhere to our rule of 

 not noticing queries which do not bear the writers' names. 



To Dealers and Others. — We are always glad to treat 

 dealers in natural history objects on the same fair and general 

 ground as amateurs, in so far as the " exchanges " offered are fair 

 exchanges. But it is evident that, when their offers are simply 

 Disguised Advertisements, for the purpose of evading the cost 

 of advertising, an advantage is taken o{ out gratuitous insertion 

 of " exchanges " which cannot be tolerated. 



We request that all exchanges may be signed with name (or 

 initials) and full address at the end. 



Special Note.— There is a tendency on the part of some 

 exchangers to send more than one per month. We only allow 

 this in the case of writers of papers. 



R. Coupar. — For list of Dr. Masters' works, address him at 

 the "Gardener's Chronicle" office, 41 Wellington Street, 

 Covent Garden, London. 



A. P. — From your sketch we judge the lizard to be a species 

 of Iguana. That is, a genus of lizards remarkable for their 



