HARDWICKE'S SCIENCE-GOSSIP. 



5J 



action they should give smoothness and uniformity 

 to the motions of the lancets, and also to act as 

 feelers, to direct as to the occasions and limits of 

 the use of the sting. This, however, is purely hy- 

 pothetical. 



It may be interesting and useful to some, to give 

 an account of my mode of preparation of the sting. 

 I use the simple microscope in dissecting; with a 

 magnifying power of about an inch focal length. I 

 remove the last segment of the abdomen of the 

 wasp and place it on a glass slide ; I then with 

 needles separate and take away the external covering 

 of the segment, and with a camel-hair pencil and 

 needles carefully wash away and separate the mus- 

 cular tissue, so as to leave the sting and brushes or 

 palpi clean, and the sheath, duct, and poison-bag 

 in a line on the slide, clean and unbroken, taking 

 especial care that the poison- bag receives no puncture 

 from the needle, or any rupture by rough treatment, 

 and that the duct from the poison-bag to the sheath 

 be plainly seen, and be not entangled in muscular 

 fibre. 



All this can be done on the glass slide, the 

 dissection being kept moistened with water sufficient 

 to cover it, without causing it to float, until every- 

 thing be removed except the parts required. I 

 then place the dissection in position in the centre 

 of the sHde, and leave the slide under a glass shade 

 for about a week, until the sting, &c., has become 

 perfectly dry, and the poison fluid in the bag, if any, 

 has had sufficient time to evaporate. Irhen moisten 

 with a few drops of turpentine, and mount immedi- 

 ately in balsam. 



I use no pressure at any time that would distort 

 the parts, my object being, not so much to make a 

 beautiful preparation, as to obtain crystals from the 

 poison fluid,';and also to see the parts of the structure 

 in their natural position. 



This method will give very interesting and 

 beautiful slides, from dissecting gall-flies and saw- 

 flies, and will sometimes bring instances of structure 

 to view singular and curious, that 1 think have not 

 yet been illustrated or explained. 

 Armagh. Lewis G. Mills, LL.D. 



A HAILSTORM. 



A LTHOUGH meteorological phenomena are 

 -'--*- not often recorded in the pages of Science- 

 Gossip, it may not be without interest to the 

 readers of its pages if I contribute a brief record 

 of a storm which passed over Edmonton on Wed- 

 uesda}', the 7th August. 1S72. I had gone there 

 shortly before seven o'clock in the evening by the 

 new line of railway recently opened by the Great 

 Eastern Railway Company, and upon approaching 

 Edmonton, the sky gave unmistakable indications 

 of a coming storm. To the right, in the direction 



of Epping Forest, the atmosphere was tolerably 

 clear, but on the left the line of tlie horizon was 

 almost lost in a heavy mass of purple-black clouds, 

 out of whicli came occasional flashes of what is 

 commonly called sheet lightning. 



Beyond this indication that a thunderstorm was 

 travelling on the west of the line of railway, there 

 was nothing exceptional to remark. On leaving 

 the new station at Edmonton to cross the old line, 

 the time being then seven o'clock, a few black 

 clouds came overhead, travelling at a great pace. 

 They were apparently so close to the earth, that a 

 child standing near to me made the expressive 

 remark, that they would fall on the houses. lu 

 another moment the nearest cloud was torn into 

 shreds, as though a violent explosion had taken 

 place in its centre, and in a few seconds more 

 followed one of the most remarkable falls of hail 

 which I have ever seen. 



Meteorological annals abound with descriptions 

 of remarkable hailstorms ; many of them so marvel- 

 lous that to believe the descriptions of them is 

 rather a tax on the imagination. 



Some Farmers' Insurance Companies have pub- 

 lished accounts of storms of ■wonderful character ; 

 but in these instances a little romance is pardon- 

 able, and when I have read of hailstones as big as 

 hen's eggs, oranges, and the like, I may perhaps be 

 excused for being a little sceptical. 



The storm at Edmonton on the 7th August, 

 however, was a fact, and as I watched it carefully, 

 and examined many of the hailstones which fell, 1 

 have no hesitation in stating what I saw. In 

 shape the stones bore the same character as those 

 described by Herschel, Howard, Clark, and other 

 observers, and although they were not so large as 

 to rival the hailstones which are said to fall in the 

 Himalayan regions, their size was sufficiently re- 

 markable. The largest stone I could find had pro- 

 jections at either end tapered 'to a point. The 

 stone bore all the appearance of having possessed a 

 number of radiating spines, if the projections ou 

 the surface may be so described. 



Of one type of hailstones there were many speci- 

 mens, varying in size from a pea upwards, and all 

 bearing the same hexagonal markings. In several 

 there was a well-marked cavity in the centre, occu- 

 pying about a third of the bulk of the stone. Upon 

 breaking such stones across, the cavity was found 

 to be dry in some instances, and filled with water 

 in others. 



During the storm, which raged for about twelve 

 minutes, the flashes of lightning were extremely 

 vivid, and followed each other at very short inter- 

 vals. When tlie hail passed over, rain followed, but 

 during the time the hail fell, there was no indica- 

 tion of rain, a feature which is, I believe, common 

 to these phenomena. 



Another circumstauca not unusual during severe 



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