166 



HARDWICKE'S SCIENCE-GOSSIP. 



[July 1, 1867. 



Killing Cockroaches. — In answer to J. G. in 

 your last number, I beg to recommeud phosphor 

 paste spread on bread and butter (I dare say almost 

 any eatable would do, but this is what I used), as a 

 remedy for Cockroaches. Some years ago my house 

 swarmed with them, but some ten days (more or 

 less) after this treatment none were to be found. 

 I am told these creatures are cannibals, and I 

 believe it is so ; and, if so, the riddance of their 

 presence is easy to be accounted for. While speak- 

 ing of these unpleasant intruders, I should like to 

 ask if any of your readers have met with intestinal 

 worms in them. I have been working at Cock- 

 roaches a little of late, and have found several with 

 these worms in the intestinal canal — all sizes, ^ to 

 ^ of an inch in length ; but all the large ones have 

 eggs in them, which generally are extended from the 

 body of the animal as soon as it dies. — W. Hcnwell. 



Nest or the Hydrophilus— Should any of your 

 readers be curious on the subject of the nests of 

 water insects, let me recommend them to procure a 

 pair of the large harmless Water-beetle {Hydro- 

 philus Pireus). Yesterday morning I saw Mrs. 

 Hydrophilus cutting up a whole water-plant of a 

 thin grassy kind, and, suspecting her purpose, I 

 removed her with the plant, and a few stray leaves 

 of another, from the aquarium to a separate jar. 

 There, she first made a white silk bag out of materials 

 provided by herself, laid a large number of eggs in 

 it, tied it up, made a basket round it of the water 

 plant, and closed it up with a handle made of another 

 plant, which she painted of a brown colour with her 

 ovi-positor : my children and I watched the whole 

 process— she was far too much absorbed to notice 

 us — the result is a thing looking like a miniature 

 swan ! the handle sticking up like the head. Can 

 any of your readers inform us how long her eggs 

 will take to hatch ? I have succeeded in hatching 

 the eggs of the water-snail, and can only suppose 

 that on former occasions the contents had been 

 devoured before we removed them. — L. H. F. 



Dead Black. — Mix lamp or vegetable black with 

 common size, or, what is still better, turpentine. I 

 should think a good instrument for the taking of 

 skeleton-leaves off blotting-paper, and moving from 

 place to place, would be a pair of forceps or tweezers, 

 as used by gold-beaters in laying the gold-leaf on the 

 books. — Geo. Scovell. 



To Easten Diatoms. — In _ reply to E. W. 

 Schoenebeck, respecting fastening the diatoms on 

 the slides, Professor Williamson adds a few drops 

 of gum-water to the last washing, which causes 

 them to adhere to the glass sufficiently to prevent 

 the balsam conveying them away. (See Davies on 

 Mounting, p. 62).— W. Fletcher. 



Daisy and Buttercup, both with Easciated 

 Stems (G. B. and A. M. M.). — In these specimens 

 it is clear that uot only is there flattening, but also 

 a fusion of several flower stalks into one. Moquin 

 Tandon, the great authority on these subjects, con- 

 sidered fasciation as the result simply of the flatten- 

 ing of a single stem.— M. T. M. 



The Zoological Society of Hamburg is 

 desirous to obtain living marine animals for the 

 aquarium. Liberal prizes will be given for desirable 

 specimens delivered near London, and collectors 

 are invited to apply in the first instance to Mr. W. 

 A. Lloyd, Zoological Gardens, ^Hamburg, North 

 Germany. 



Weather-wise.— In the country the weather pre- 

 dictions which are the most popular next to those 

 of Moore's or Poor Richard's Almanacks depend 

 upon the estimation of trees as thus : — 



If the Oak's before the Ash 

 We may then expect a splash, 

 With the Ash before the Oak 

 We are sure to get a soak. 



The simple meaning being, that if the leaves of the 

 ash come out before those of the oak we are to 

 expect but a splash or dash of wet for that season; 

 but if the oak take precedence, much wet is to be 

 expected. Now, as I happened to travel from 

 Dorset to London on the 10th of May of the pre- 

 sent year, I noticed that while the oak was almost 

 sufficiently leafy to conceal a king, the ash was one 

 uniform bundle of bare twigs ; but, strange to say, 

 that this state of things only continued as far as 

 Swindon, as from a little beyond Swindon, and 

 more certainly in the London district the ash was 

 the most forward. Are we, then, from these facts, to 

 predicate a different summer for the west from that 

 of the east; and, if we are not, "Erancis Moore, 

 physician," and Old Richard ought to have left us 

 eastern and western weather predictions ? Some 

 years there is good reason for gardening and farm- 

 ing according to the behaviour of the leaves of 

 the elm-tree, as thus : — 



When the elmen leaf is as big as a farding, 

 It's time to sow kidney beans in the garding ; 

 When the elmen leaf is as big as a penny, 

 You must sow beans if you aim to have any. 



But also for this year those who obeyed the first 

 injunction have suffered woefully! Nay, more, — 

 even the cautious ones who waited for the penny size 

 have in the west suffered grievously from the frosts 

 of the 22nd, 23rd, and 21th of May, and, indeed, we 

 are all sowing afresh. It remains to be seen how 

 far this kind of almanac will be right as regards 

 barley sowing, the country legend being as fol- 

 lows : — 



When the Elmen leaf is as big as a mouse's ear, 



Then to'sow barley never 'fear. 

 When the Elmen leaf is as big as an ox's eye, 



Then says I, "hi boys, hi ! 



As a rule, barley may safely be sown as soonas the elm- 

 buds burst ; but if left until the leaf is nearly grown, 

 it will be usually too late to insure a good crop ; but 

 this year some of the earlier sown barleys have suf- 

 fered like most other things from an unusually 

 severe spring. These remarks may, perhaps, serve 

 to show that it is as difficult to make weather pre- 

 dictions come true bv rhyming as it is by reasoning. 

 —J.B. 



Dead-black. — The dull-black used by opticians 

 for "coating" the insides of microscope and tele- 

 scope tubes, is a mixture of the best " lamp-black " 

 and "lacquer." The former should be _ well 

 pulverized, adding sufficient of the latter to give it 

 the fluidity of ink. If too much lacquer be present, 

 a "glossy" instead of a "dead" surface is the re- 

 sult. It may be laid on with a sable brush after 

 shaking the bottle, and the tubes must be heated to 

 insure quick evaporation. — Thomas Curties. 



Sticking Diatoms— In your last number Mr. 

 E. W. Schoenbeck inquires how diatoms may be 

 made to stick on the slides before being mounted in 

 balsam. If he will place a thin film of a very weak 

 solution of gum on the slide, and then deposit the 

 diatoms in it, and allow it to dry, he will lind them 

 sufficiently fixed to prevent their being floated out 

 by the balsam.— T. W. G. \ 



