HARDWICKE'S SCIENCE-GOSSIP. 



2S3 



Destroying Moles.—" R. B. H." may destroy 

 moles effectually by procuring a quantity of large 

 earth-worms and cutting each in two ; then sprinkle 

 them well with powdered nus vomica, find the run 

 or burrow of the animal by piercing the ground with 

 an iron-pointed rod or with al pointed stick : near 

 the hedge is the best place, as that is generally their 

 home. Cut out a piece of the ground rather wider 

 at the surface than at the bottom, by making four 

 cuts, one at each end, and on each side remove the 

 earth carefully with a small sharp spade ; then put 

 in the run a quantity of the doctored worms with a 

 stick, and replace the earth, the neater the better, 

 as moles will alter their runs rather than work in 

 the light. In a few days spread the molehill to 

 see if they still throw them up ; if not, they are 

 all done for ; but if any fresh hills are seen, repeat 

 the dose. Early in April is the best time for 

 doing it, as fresh soil is thrown to the surface, 

 and moles often do much good by their inartistic 

 work.— i^. V. 



Palates of Spiders. — Will P. Burnard, who 

 wrote a short article on " palates of spiders " in the 

 May number of this magazine, mind inserting a 

 notice in next month's Sciexce-Gossip, stating his 

 method of preparing insect specimens with carbolic 

 acid and chloroform ? I have tried it, and found it 

 a very expeditious way of mounting, but I totally 

 failed in making good slides, because I could not by 

 any means get rid of the "interior arrangements," 

 which on being pressed squeezed out. — H. M. J. 

 JJnderhill. 



Sending Objects bt Post. — In last number of 

 Science-Gossip I find a communication from "A. S." 

 stating that the plan I recommended for sending 

 microscopic slides by post has been known for years, 

 &c. "A. S." may may not have meant it, but his 

 communication reads exactly like — If he supposes 

 he has found out anything new, let me tell him it is 

 " as old as the hills," as the saying is. Now if your 

 readers will turn to the number of Science-Gossip 

 for last September, page 214, they will find that so 

 far from claiming any merit (if there be any) for the 

 idea, I distinctly stated that "I do not claim the 

 merit of the invention. It is by no means new, 

 but nevertheless does not appear to be known to 

 many ; " and I was led to this conclusion by the 

 very frequent complaints of objects, &c., being re- 

 ceived by f ou in so smashed a state as to be utterly 

 useless. I have only to add that the plan of a 

 detached label bearing the stamps and address is 

 needed only when the containing box is slight, — as 

 "chip," or "cardpaper," &c. But as we can now 

 (thanks to " Sir Roland-le-Grand") send our slides 

 in boxes made of half-inch plank, if we please, of 

 course the detached label precaution is needless. 

 -E. U. J. 



Wood Ants. — Wliilst opening a nest of wood 

 ants {Formica nifa) I observed that they possessed 

 the power of ejecting a liquid from the extremity of 

 the abdomen to a distance of eight or ten inches. 

 The drop was about the size of a small pin's head, 

 and one individual was able to perform the feat three 

 or four times in succession. When in the act of 

 discharging the liquid (formic acid), the abdomen 

 was bent under the thorax, an attitude which they 

 always assume when alarmed. 1 should be obliged 

 if you could tell me whether this fact is generally 

 known, and also give me any more information on 

 the subject, as I have never observed it hitherto. 

 The time of observation was at the beginning of 

 this month (October). — N. 31. Bic/iardson. 



Horse-eye Nut.— Can any of your correspond- 

 ents inform me what is the proper name for the 

 nut called commonly Horse-eye nut, — whether it is 

 the same as the Calabar bean {Physostigmatis fubayi 

 I tliink it is, the form being the only difference. 

 — W. E. 



Trachinus.— The fish mentioned by the Echo 

 correspondents may be either Trachinus Draco, the 

 Sting-gull or Catfish, or the Trachimis Vipera, Little 

 Weaver, Otterpike (see Couch, vol. ii. p. 483 ct 

 seq.). The latter is common at the mouth of the 

 Tyne. 'The shrimpers generally carry a small bottle 

 of sweet oil to apply in case they are stung. I have 

 seen persons after being stung : there was great 

 swelling, and discoloration almost to blackness. 

 The swelling generally goes down in twenty-four 

 to thirty-six hours, discoloration perhaps lasts 

 longer; I have, however, never heard of a case 

 being so bad as neai'ly requiring amputation. — 

 R. Y. Green. 



Cement for Aquaria.- A rectangular tank of 

 about ten gallons capacity, and constructed of plate- 

 glass with a zinc bottom and massive wooden pillars, 

 troubled me much for a long time by leaking. It 

 was cemented with red and white lead, covered with 

 a coating of shellac varnish, and was constantly being 

 recemented in the faulty places ; but after the lapse 

 of three weeks or so, it would leak afresh ; and this 

 went on till, in despair, I was forced to give up re- 

 pairing it as a bad job. Some time after, a friend 

 recommended a cement composed of resin, tar, and 

 linseed-oil, which he assured me was the best for the 

 purpose of making water-tight this troublesome 

 aquarium. I therefore tried it without delay, and I 

 am pleased to relate that the said aquarium has now 

 been standing just a year with the water unchanged, 

 and shows no signs of leakage whatever. I cannot 

 give the exact proportion of each ingredient of which 

 this cement was composed, but i used about an 

 eggcupful of oil and 4 oz. of tar to I lb. of resin, 

 and allowed them to melt together in a pipkin over 

 a gentle fire. If much oil be used, the cement will 

 in all probability run down the angles of the aqua- 

 rium : to obviate this it should: be tested before use 

 by allowing a small quantity to cool under cold 

 water, and if not found suificieutly firm, allowed to 

 simmer longer, or have more tar and resin added, 

 which will answer the same purpose. The cement 

 should be poured in the angles of the aquarium 

 while in a liquid state, but not when boiling, or it 

 would most assuredly crack the glass. The cement 

 will become firm in a few minutes, and the aquarium 

 may then be tilted up in a different position while 

 a second angle is treated likewise ; and so on till 

 the whole work is completed. I think " W. K. G." 

 would find this more suited to his purpose than 

 "coaguline," which is so precious for many purposes, 

 out which for this work seems hardly coarse enough. 

 This combination of tar and resin adiiercs firmly to 

 the glass, is so pliant that it may be pressed into 

 any shape with the finger, and it does not communi- 

 cate any poisonous quality to the water. — Henry A. 

 Auld. 



Snakes and Toads.— I see that in the July 

 number of Science-Gossip, W. H. Warner 

 inquires whether " the snake swallows toads." 

 I believe such to be the case, though it is not such 

 a favourite repast as the frog, since it is able to 

 exude an acrid matter from its skin, which is 

 covered with glandular warts. It is preyed upon 

 by owls, buzzards, &c., besides snakes. — A. F. E. 



