Notes and Memoranda. 481 



found an account of the great storm of the 7th of May, as it operated, in the 

 valley of the Scheldt. The most remarkable feature was the enormous 

 quantity of hail. M. Lermoyer states that at Yendhuile the hailstones were 

 as large as musket-balls, at Catelet they reached the size of a pigeon's egg, and 

 even of a fowl's egg ; these great ones being composed of agglutinations of 3 those 

 of smaller dimensions. The storm of hail and rain began at 4h. 30m. p.m., and 

 was accompanied by formidable whirling gusts of wind. A ditch attached to the 

 canal of St. Quentin, and which received the drainage of 500 hectares (about 

 1235 square acres) of land, was so overfilled by the hail and rain as to overflow 

 the high bank of the canal, and sweep into it 800 hectolitres of firewood, 

 obstructing the navigation. The hail formed a congealed mass 462 metres long, 

 and 20 in mean breadth, or about 459 yards long, and nearly 22 broad. " This 

 deposit constituted a veritable glacier ou which it was safe to walk." When a 

 channel was cut through it, detached masses floated down like icebergs above the 

 bridge of Vendhuile, the meadows of Ossu were covered for a mile and a-half 

 with a mass of hailstones more than 200 yards wide. It was observed that 

 during this storm vanes placed on heights indicated north-east currents, while 

 those in the plains showed south-west. 



Ok some Peopeeties op 1S t iteic Acid. — M. Dietzenbacher informs the 

 French Academy that very remarkable oxydizing powers are exhibited by heating 

 a mixture of fuming nitric acid and Nordhausen sulphuric acid. Charcoal and 

 lamp-black burn eaergetically in such a mixture. The acids, mixed in equal 

 proportions, transform cotton in a few seconds into pyroxylin, insoluble in ether 

 or alcohol ; thus prepared it burns instantly, leaving no residue. Cotton par- 

 tially submerged ignites and discharges thick vapour. Zinc, which is ener- 

 getically attacked by concentrated nitric acid, remains for days in the mixed acids 

 without alteration. The mixture is equally inactive towards iron, copper, and 

 tin ; the iron does not become passive. 



Peeseevation of Wines. — M. Pasteur recommends that the disorders of 

 wine, which are occasioned by parasitic ferments, should be arrested by heat. He 

 bottles the wine, wires the cork, and exposes it in a hot-air stove to a temperature 

 of from 60 3 to 100° C, or 140" to 212= Fahr. The cork, which is partly driven out 

 by the heat, is replaced when the wine cools and sealing-wax applied. M. Pasteur 

 states that this process prevents the action of the ferments, and has not broken a 

 single bottle in his experiments. M. de Vergnette-Lamotte, who made inde- 

 pendent experiments, also recommends the application of heat. Of course some 

 years must elapse before the effect of the process can be fully known. According 

 to M. Lamotte, a temperature of 40" O, or 104° Fahr., rapidly causes wine to 

 assume the properties conferred by age. 



Phosphoeescence at Sea. — On the 4th of September, at nine p.m., M. B. 

 Coste noticed in lat. 9 N., long. 50 (French), what the French sailors call a "sea 

 of milk", (mer de lait). It approached the ship in the form of a great sheet of 

 white phosphorescent water, looking as if the sea were covered with snow as far 

 as the horizon. The appearance was occasioned by myriads of minute gelatinous 

 creatures, which he denominates noctiluca, miliaris, though his description does not 

 indicate that animal, which is nearly spherical, while those he saw were like " little 

 straws covered with silver." Contrary to what is usual, and what he had noticed 

 before, the furrows made in the water by the passage of the ship were dark and 

 not luminous. 



Monochkomatic Light poe the Miceoscope. — The Abbe Count Castracane 

 states that by employing M. Foucault's heliostat and a prism of large dispersion, 

 he illuminates the Pleurosigma angulatum, or other objects with any kind of mo- 

 nochromatic light. In the case of the P. angulatum he finds a bluish green exhibits 

 the markings with a much lower power than when white light is employed. The 

 account of the experiments, which we find given to us in the Archives des Sciences, 

 is not intelligible to us as regards the powers employed. It says that with white 

 light the filth and strongest objective of an Amici microscope was neces3ary to 

 resolve the markings of the diatom, while the third objective would do it with the 

 monochromatic rays. 



