90 



HAPDWICKE'S SCIENCE-GOSSIP. 



fetidus (L.) and Atropa belladonna (L.) both grow 

 in profusion there, but are not indigenous to the 

 spot. — Walter W. Reeves. 



The Cause and Prevention of Mouldiness 

 in Fern-cases.— On looking over the back volumes 

 of Science- Gossip, I observed inquiries respecting 

 the prevention of mouldiness among ferns ; but I also 

 noticed that in the several replies not one contained 

 a correct answer to the question. Some years back 

 I met with the same difficulty, and did not let the 

 matter rest until I had obtained a complete explana- 

 tion of the whole subject. Inan ornamental fern-case, 

 standing upon a bronzed table, everything placed 

 within it persisted in not growing, but in becoming 

 covered with mildew and mould, and even the earth 

 itself produced prolific crops of fungi, until at last it 

 was suspected that some detrimental influence must 

 be at work, either from material or construction, and 

 on making a closer scrutiny, such was found to be 

 the reality. The framework of the case being of 

 zinc, and the bronzed table of iron, and as neither 

 the bottom surface of the former, uor the upper 

 surface of the latter had been painted, the two 

 metals were in actual contact, and they formed a 

 galvanic combination which proved to be the ruling 

 cause, for on separating the metals by an insulating 

 support of wooden bars, the plants at once became 

 healthy and took to growing, and all symptoms of 

 mildew and fungi entirely vanished, and have never 

 made their appearance since. From this discovery 

 it was at once perceived that polar influence was 

 paramount in the laws of growth, and by the appli- 

 cation of these principles it has been found that we 

 possess a practical control over many of the " ills 

 that flesh is heir to," both in plants and animals, 

 while it has also given us a clue to the cause and 

 prevalence of fungoid growths, and a ready means 

 of overruling their production. Under one of the two 

 polar conditions root-action is fostered, and when 

 interfered with, fungoid growths are encouraged ; 

 while, by reversing the polarity, the latter disappear 

 and atmospheric growth is promoted. Mildew in 

 vineries has been overcome and banished, and by 

 standing pot-plants on iron so as to excite polar 

 action at the roots, an unusual healthiness has been 

 obtained. By galvanic influence seeds have been 

 made to germinate heels upwards, or with the 

 radicle in the air, and the plumule downwards. 

 Roses or other plants trained to iron stakes will be 

 found to have their stems in contact with the iron 

 blackened and killed ; plants trained to galvanized 

 wire fastened with iron nails become unhealthy 

 and cankered, and numerous other effects may be 

 traced to the same "galvanic" cause, the obvious 

 remedy for which is to reverse the polarity, or to 

 prevent it as much as possible by insulation and 

 non-contact with the atmosphere. These experi- 

 ments will be found more fully treated in the series 



of letters which appeared in the Gardener's Chro- 

 nicle, commencing November 23, 1872, commented 

 on in an editorial article, Dec. 14th, aud continued 

 Jan. 11, 1873, Feb. 1, Feb. 22, and March 8 ; 

 and in which the long-desired connecting-link 

 between the electricity of the atmosphere and 

 organic life, and other polar effects upon inorganic 

 matter are pointed out and explained. — W. Kencely 

 Bridgman. 



GEOLOGY. 



Geological Record. — The volume of the 

 "Geological Record" for 1874— the first of its 

 kind — has just made its appearance, under the able 

 editorship of Mr. W. Whitaker, F.G.S. All the 

 papers bearing on geology and palaeontology, pub- 

 lished at home and abroad, during 1874, are ably 

 catalogued and abstracted. Mr. Whitaker has besn 

 assisted by some of the best and most rising geolo- 

 gists of the day, and the volume is not only credit- 

 able to the industry of English geologists, but it is 

 a most valuable necessity to a geological library. 



The Ceratodus. — In reference to Professor 

 Huxley's lecture on Ceratodus (Science-Gossip, 

 p. 40), are your readers aware that there is, in the 

 Bristol Museum, a unique collection of Ceratodus 

 teeth from the Phytic beds of Aust Cliff, near 

 Bristol, associated with bones of the saurians ? 

 More than 400 different forms of these fossil teeth 

 have been described under the name of Ceratodus, 

 or homed teeth, from certain lateral prominences 

 that render them remarkable. Mr. E. T. Higgins 

 made the largest collection of these teeth, which 

 was eventually 'purchased by special effort for the 

 sum of £250, and added to this far-famed geological 

 museum. No other portions of the fish were found, 

 therefore the original nature of the Ceratodus could 

 not be ascertained with certainty, even at the 

 accomplished hands of Professor Agassiz, until, 

 "in 1S70, the Hon. W. Forster showed to M. 

 Kreft, the curator of the Sydney Museum, a carti- 

 laginous fish that lived in Queensland, and whose 

 teeth corresponded in every respect with those of 

 the fossil Ceratodus" except in size. It presents 

 another interesting example of the Dipnoi, or 

 double breathers, because it can breathe with lungs 

 or gills, either separately or conjointly. It is an 

 herbivorous amphibious fish, not exactly a true liver 

 out of water, but occasionally works its way into 

 the muddy banks, and when warm weather sets in 

 buries itself in the mud, until the wet season 

 returns. "It is worthy of note that the nature of 

 the habitats of the fossil fish exactly corresponds 

 with that'of the recent. They lived in dismal, 

 muddy flats, and buried themselves in lumps of 

 clay, aud using their lungs, breathed through a 

 hole purposely made for communication with the 



