HARD WICKE'S SCIENCE- G OS SIP. 



95 



Hill, Essex) V. vulgaris and V. Germanica abound, 

 V. sylvestris and V. rufa are uncommon, while V. 

 JSforvegica and the hornet are decidedly rare. The 

 seventh species, V. arborea, is of course absent. Your 

 correspondent is extremely fortunate to have collected 

 in one year queens of all the species. What is his 

 district ? I should be very glad to see his specimens, 

 and, if he desires, to name them for him. — F. W. 

 Elliott. 



Gas beneath Ice. — In answer to the inquiry of 

 your correspondent W. C. P., I think there is no 

 doubt that the gas let out from beneath the ice on 

 the pond at Fairburn was what is commonly known 

 as marsh gas, a compound of carbon and hydrogen 

 (CH 4 ), and a result of the^decay of the under layers 

 of the peat bog which are excluded from the air. — 

 Alice Bradlaugh. 



Curious Phenomenon on Ice. — The inflam- 

 mable gas which, according to your correspondent 

 W. C. P., was observed beneath the ice on his 

 friend's curling pond, was probably light carburetted 

 hydrogen (CH 4 ), or "marsh gas," as it is also called. 

 This gas is generated by decomposing vegetable 

 matter, and thus occurs in most stagnant ponds and 

 marshy places. — W. C. Flood. 



Curious Phenomenon on Ice. — I have no doubt 

 from the data furnished by W. C. P. that the gas 

 which escaped from holes made in the ice of his peat 

 pond was marsh gas, the first of a series of bodies 

 known as paraffins. Marsh gas, methane, carbu- 

 retted-hydrogen, and fire-damp, as it is variously 

 named, according to its occurrence in nature, fre- 

 quently appears in stagnant pools, being produced by 

 the decomposition of vegetable matter — hence its 

 designation " marsh gas." In coal mines it oozes 

 out from pores in the coal, where it has been occluded 

 since its formation, and forms the much-dreaded 

 " fire-damp," which on ignition burns, like W. C. P.'s 

 escaping gas, with a scarcely luminous bluish flame. 

 If mixed with the oxygen of air before lighting it 

 causes a terrific explosion, with the production of 

 carbon-dioxide, the " choke-damp " of miners. Al- 

 though extremely explosive, this gas is not thought 

 to ignite spontaneously. " It is also found in volcanic 

 gases. The gas of the mud volcano at Bulganak in 

 the Crimea is nearly pure methane." — W. E. 

 Watkins, Barnsbury, N. 



Note of the Cuckoo. — W. C. P. will find that 

 there is nothing new in the cuckoo crying cuck-cuck- 

 coo. It is as Mr. H. Lamb says, a common occur- 

 rence. Probably it is not a gift of any cuckoo or 

 cuckoos in particular, but any cuckoo is apt to do 

 so when excited. The bird sings cuckoo in a slow 

 and measured tone, but the cuck-cuck-coo is jerked 

 out in a much more hurried fashion ; and it some- 

 times even cries cuck- cuck-cuck-coo when the notes 

 follow each other in still more rapid succession, as 

 though the bird was under some strong excitement at 

 the time. — IV. Holland, Southampton Street, Reading. 



The Note of the Cuckoo. — I think Mr. Lamb's 

 suggestion in your January number is incorrect, as I 

 have myself watched a cuckoo from a short distance 

 (twenty yards). It was seated on the top rail of a 

 gate, and afterwards removed to the bough of an oak 

 tree. At intervals it repeated the three notes " cuck- 

 coo-coo." I can see no reason for thinking that it 

 does not voluntarily utter the note by the action of 

 its throat ; and should consider it hardly possible 

 to obtain so loud a sound by the means H. L. 

 suggests. — Gresham F. Gillett. 



Poterium Sanguisorba. — I do not see mention 

 of this plant in Dr. P. Q. Keegan's catalogue of wdd 

 flowers around Ullswater. I picked it in the meadows 

 at Grassmere last year, where it presents a remarkable 

 appearance, being upright, sepia green in colour, 

 with acuminated leaflets and purplish flowers ; 

 whereas, on the Surrey Downs, it is prostrate, yellow- 

 ish, with ovate leaflets and greenish flowers.— A. II. 

 Swinton. 



Mimulus luteus. — What does P. Kilgour imply 

 by " annular plant stems"? I presume annual is 

 a more common rendering of his meaning, for I 

 cannot find any reference to a ringed condition of 

 the stem of Mimidus luteus, L., in Sir J.'D. Hooker's 

 " Flora of the British Isles," 3rd edition. If my 

 former suggestion be correct, I think P. Kilgour will 

 discover (?) several annual plants in which the fibro- 

 vascular ring is completed by the development of 

 Phloem and Xylem from the interfascicular cambium ; 

 that is, if he will give it time to grow. — A. W. L. 



NOTICES TO CORRESPONDENTS. 



To Correspondents and Exchangers. — As we now 

 publish Science-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 sp 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 of ovct 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. 



I. Ingham. — Many thanks for offering to send us a specimen 

 of the " Daily Telegraph's Meteorite." You will see in our 

 last number that a fragment had been sent us, and that was a 

 fragment of ordinary mottled carboniferous sandstone. 



J. T. F. — The " Popular Science Review " ceased to be 

 published in 1878. Apply to Mr. W. P. Collins, 157 Great 

 Portland Street, for back numbers or volumes. 



A. E. Forsham. — The best books on the subject you mention 

 areiBell's " British Reptiles " (Lovell Reeve & Co.), and Cooke's 

 "British Reptiles" (Allen & Co.) 



J. A. — We have not heard of Mr. Ady's " Studies" since the 

 last issue was noticed in Science-Gossip, and therefore we 

 conclude they are discontinued. We do not know his address. 



W. H. L. — You will find in the Microscopical column, and 

 also in aiticles of back numbers of Science-Gossip, many 

 recipes for preserving animal matter for mounting. 



J. B. — Sach's "Botany" is of the first order; so is the new 

 edition of " Vine and Prantli." 



E. B. — You will see our remarks as to the supposed Barnsley 

 " meteorite " above. 



X. Y. Z. — You had best offer your services to some of the 

 chief microscope makers and dealers in microscopical materials. 



W. J. Tabley. — You will find the fullest particulars as to the 

 "plate cultivation" of bacteria, etc., in Dr. Crookshank's 

 " Introduction to Practical Bacteriology," published by H. K. 

 Lewis. 



E. Brunetti. — Will you kindly send us your full address. 



EXCHANGES. 



Offered, Science-Gossip, 1878, unbound ; "Midland Natu- 

 ralist," unbound ; Tripp's " British Mosses," 2 vols. ; Watson's 

 "Topographical Botany;" "Lessons in Elementary Botany," 

 by Daniel Oliver; "Countries of the World," 6 vols. (Cassell) ; 

 " Cities of the World," unbound (Cassell) ; " Knowledge," un- 

 bound, No. 1 to present. Wanted, "The Power of Movement 

 in Plants," by Darwin ; " The Expression and Emotions in 

 Man," by Darwin; "The Variation of Animals and Plants 

 under Domestication," by Darwin ; "The Naturalist's Jour- 

 nal ;" " Records of a Naturalist on the River Amazon," by 

 H. W. Bates. — Thomas Hebden, Hainworth, near Keighley. 



