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SCIENTIFIC NEWS. 



199 



red-hot, electricity was again discharged through the point. 

 Nahrwoldt concluded that this was due to particles flying 

 from the red-hot wire. This conclusion was proved to be 

 correct by the occurrence of platina in the deposits on the 

 sides, and by the loss of weight of the wire. These experi- 

 ments led him to the conclusion that air free of dust cannot 

 be electrified statically. 



Photographic Schools in Austria and Germany. — 

 More and more attention is given in this country to the fact that 

 a scientific education of those young men who intend to em- 

 brace photography as a profession becomes a necessity. 

 In a few months there will be opened at Vienna, under the 

 direction of the eminent professor Eder, a photographic 

 school, in which instruction will be given in all photographic 

 and photo-mechanical processes. There is no doubt this 

 newly established school will do much good to the young 

 professional photographer who has visited it ; the education 

 received will guide him in his professional duty, and estab- 

 lish his social standing. Also at the technical academy of 

 Karlsruhe (Baden) instruction will be given in photography 

 from this month forward. Herr Fritz Schmidt, of Breslau, 

 the well known teacher of scientific photography, has been 

 appointed as professor, and according to the programme, he 

 intends to instruct in photography — collotype (lichtdruck), 

 and kindred processes — with regard to its scientific, techni- 

 cal, and artistic application. Besides this there has been 

 for many years a photographic private school at Gronenbach, 

 Bavaria, the proprietor of which is the well deserving photo- 

 grapher and collotyper, W. Cronenberg. In this establish- 

 ment, beautifully situated in the midst of pleasant meadows, 

 and in the sight of the Bavarian Alps, hundreds of scholars 

 of all countries have received a most careful instruction in 

 all branches of the old and new photographic process. — 

 Photographic Ne'ws. 



Protecting Iron against Rust. — La Mc/u/Ziirgw describes 

 a metallic compound for the protection of iron, consisting of 

 a solution of aluminium in palmitic acid. A product is 

 thereby obtained which has the property of dissolving zinc 

 in large quantities. In this manner an alloy of aluminium 

 and zinc is produced which costs but little, as only a small 

 quantity of aluminium is present. This is applied with a 

 brush to the iron, which is thus effectually protected against 

 oxidation. The Illiistn'rtc Zcitiing fiir Blcchindiistric quotes 

 a communication on the above subject from Herr Busse, of 

 Hanover, who states that some years ago he pointed out 

 that bright iron and steel articles could be successfully pro- 

 tected by super-oxidised linoleine acid against the formation 

 of rust, without any injury to their metallic lustre. It is 

 remarked that a simple and efficacious preventive of rust 

 must necessarily be welcome in most workshops, as after a 

 great deal of trouble has been taken in producing a brilliant 

 polish, a small quantity of moisture produces oxidation. 

 The hydrate of linoleine acid is as elastic as indiarubber, 

 and its wine-yellow syrupy solution, when thinly applied 

 to metallic objects, forms a transparent, hardening, elastic, 

 and extensible layer which prevents oxidation. The bright 

 portions of ironwork have first to be cleaned with a woollen 

 rag from grease, dirt, and damp ; the rust-preventing solu- 

 tion being then thinly applied with a soft brush. By care- 

 ful treatment the metal surfaces lose none of their bright- 

 ness, and on account of the elasticity of the composition, 

 it does not crack if the metal is bent or becomes extended. 



An Electric Boy. — An American journal gives the fol- 

 lowing account of the " electrical boy " mystery : Johnny 



Norton, who a few years ago was well known all over the 

 country as Bunnell's " electric boy," is now working in this 

 city as a compositor. In reply to the query of reporter as 

 to what had become of his electricity, he said : " When I 

 was on exhibition I was enclosed in an oblong stall about 

 seven or eight feet long, the front of which was like a narrow 

 counter. Opposite the counter was a rail which only allowed 

 the visitors to pass in single file. A long strip of cocoa mat- 

 ting served as a carpet for the passage-way and also for a 

 cover for a sheet of zinc, which extended beneath it, running 

 the length of the stall. My box was similarly invested with 

 zinc and matting. Attached to the sheets of metal, but hid- 

 den from view, were the two poles of a galvanic battery, one 

 under my feet and the other in the passage. Now, anyone 

 passing over the zinc and touching me behind the counter, 

 completed the circut and received a shock. So did I. The 

 matting, of course, had to be kept damp, water being the 

 conductor. It was surprising what intelligent people were 

 duped by this trick. Why, I was kept shaking hands and 

 being fingered from morning until night. Many is the two- 

 dollar note I received from doctors and others for a couple 

 of drops of my blood for analysis. One evening three or 

 four young students came in to unmask me. One of them 

 made a wager that he would electrify the audience the same 

 way if he was in the box. I immediately invited him in 

 and he accepted the challenge. I then retired, but before 

 doing so I pressed a hidden button that cut oft' my wire. 

 He, of course, failed and ignominiously retreated, after being 

 guyed unmercifully by those present. This proved me genu- 

 ine to the satisfaction of everyone in that town, and I became 

 famous. There was a lot of fun in the business ; but I had 

 to give it up, as the constant strain caused by the battery 

 was too much for me." 



Curiosities under the Sea. — As to the quantity of light 

 at the bottom of the sea, there has been much dispute. 

 Animals dredged from below 700 fathoms either have no 

 eyes or faint indications of them, or else their eyes are very 

 large and protruding. Another strange thing is that if the 

 creatures in those lower depths have any colour, it is orange 

 or red or reddish-orange. Sea anemones, corals, shrimps, 

 and crabs all have this brilliant colour. Sometimes it is 

 pure red or scarlet, and in many specimens it inclines 

 towards purple. Not a green or blue fish is found. The 

 orange-red is the fish's protection ; for the bluish-green 

 light in the bottom of the ocean makes the orange or red 

 fish appear of a neutral tint, and hides it from its enemies. 

 Many animals are black, others neutral in colour. Some 

 fish are provided with boring tails, so that they can burrow 

 in the mud. Finally, the surface of the submarine moun- 

 tain is covered with shells like an ordinary sea beach, show- 

 ing that it is the eating-house of vast shoals of carnivorous 

 animals. A codfish takes a whole oyster in his mouth, 

 cracks the shell, and sucks out the meat. In that way 

 come whole mounds of shells that are dredged up. Not a 

 fish bone was ever dredged up. A piece of wood may be 

 dredged up once a year, but it is honeycombed by the bor- 

 ing shellfish, and falls to pieces at the touch of the hand. 

 This shows what destruction is constantly going on in these 

 depths. If a ship sinks at sea with all on board, it would 

 be eaten by fish, with the exception of the metal, which 

 would corrode and disappear. Not a bone of a human body 

 would remain after a few days. It is a constant display of 

 the law of survival of the fittest. Nothing made by the 

 hand of man was dredged up after cruising for months in 

 the track of ocean vessels excepting coal clinkers shovelled 

 overboard from steamships, but twenty-five miles from land 

 there was dredged up an india-rubber doll. This was one 

 thing the fish could not eiA.— Liverpool Echo. 



