Nov. 1st, 1 88;.] 



SCIENTIFIC NEAVS. 



20I 



better adapted for getting up aniline blacks upon cotton 

 goods than any other substance known, \:hilst an almost 

 infinitesimal quantity is sufficient to produce the desired 

 colour. Now in the Thomas slag, as turned out at the 

 Creusot iron-works in France, vanadium is found at the 

 rate of one quarter per cent. As the other substances pre- 

 sent do not in the least interfere, a simple solution of the 

 slag in hydrochloric acid answers the purpose without the 

 somewhat tedious and expensive process of separating out 

 the vanadium in a state of purity. Thus we see that an 

 improvement in the iron manufacture confers quite unfore- 

 seen benefits upon the calico-printer. 



Among the declining manufactures of the day may be 

 mentioned potassium ferrocyanide, more familiarly known 

 as prussiate of potash. Its main uses were in dyeing cer- 

 tain blues on textile goods, and in the manufacture of 

 Prussian blue. But prussian blue as a pigment has been 

 almost superseded by artificial ultramarine, which is cheaper 

 and more beautiful, though far less permanent. Meantime, 

 also, the prussian blues and royal blues on cotton and 

 woollen goods, and still more on silks, are almost aban- 

 doned in favour of the aniline blues, which are not only 

 finer but much more easily dyed. Hence the production of 

 prussiate of potash has declined to very small quantities. 

 Its chief residual product was a kind of carbon which, being 

 derived from animal matter, was in fact an animal charcoal, 

 and possessed similar properties, though it was to be had at 

 a mere fraction of the price of bone-black. Hence it served 

 for sanitary purposes. Now it is scarcely procurable, and 

 those who employed it have to look out elsewhere. It is a 

 fortunate circumstance that this carbon did not become the 

 basis of any important manufacture. 



We spoke above of the alkali manufacture by the Leblanc 

 process, and of one of its by-products. But this process 

 leaves great quantities of a refuse of a very undesirable 

 nature, known as vat waste, tank waste, or alkali waste. In 

 districts where the alkali manufacture flourishes are to be 

 seen huge heaps of this refuse giving off offensive fumes 

 and proving a nuisance wherever it is put. It has been 

 tried as a manure with the effect of rendering the land 

 barren for years. It can be used in the manufacture of 

 hyposulphite of soda, a substance much used in photography. 

 But all the consumption required for this purpose did not 

 perceptibly afi'ect the extensive heaps ot waste. 



Some very ingenious processes were devised for extract- 

 ing the sulphur, which this waste contains in large propor- 

 tion, so that it may be used over again in the manufacture 

 of sulphuric acid. Three of these processes are actually in 

 use, and a certain proportion of the sulphur is profitably re- 

 covered. Still it can scarcely be denied that there is room 

 for further ingenuity in this direction. 



The woollen manufacture is unpleasantly notorious for 

 the quantity of refuse which it produces. It is asserted 

 that for every ton of cloth which leaves a manufactory for the 

 market, there are turned out two tons of refuse, serving 

 mainly to pollute the streams. Of these, however, one of 

 the most important and unsightly, to wit, the soap-suds from 

 cleansing the wool and from fulling the cloth are now arrested 

 in catch-pits. When a sufficient quantity is thus collected, it 

 is treated with sulphuric acid, which causes the fatty matter 

 to separate out and rise in cakes to the surface. It is with- 

 drawn, washed, purified to some extent, and may then 

 serve for the manufacture of lubricants or for soaps of a 

 low quality. The soda, ammoniacal liquor, and urine used 

 in scouring the wool have hitherto utterly run to waste, nor, 

 according to our present knowledge, does their utilisation 

 seem probable. The same must be confessed of the 

 coloured liquids obtained on rinsing the wool, the yarns, or 

 pieces, after dyeing. They contain but a very minute 



quantity of different colouring matters mixed together and 

 diffused through a great bulk of water. No attempt to 

 separate them from it and from each other has hitherto 

 proved remunerative. 



Spent dye-woods and waste tan have been proposed 

 as materials for the manufacture of acetic and of oxalic 

 acids. Hitherto the results have not been very encourag- 

 ing, and now both these kinds of refuse, after drying, 

 are burnt in the engine furnace. There is here, therefore, 

 room for a better method of utilisation. 



We may conclude this brief sketch of the purposes to 

 which industrial refuse has been or may be put, with a 

 glance at the most splendid instance of its utilisation. The 

 extraction of beautiful dyes, and latterly of medicines, from 

 coal tar has so often served to " point a moral and adorn a 

 tale" that it may well pall on the reader's ear. Liebig, now 

 many years ago, said that wc might obtain from coal-tar 

 whatever we wished if wc only knew rightly how to search 

 for it. He did not say, however, that we could always ob- 

 tain it remuneratively. Of the commercial failure of such 

 an attempt the artificial production of indigo has been a 

 warning example. It is also instructive that the manufac- 

 turers of coal-tar products often find themselves now unable 

 to offer for the tar a price which gas producers think remu- 

 nerative. Hence, not a few gas-managers have been, as of 

 old, studying the results of its use as fuel under their re- 

 torts. 



One great difficulty which besets all attempts at the 

 utilisation of refiise — and which has particularly pressed on 

 the tar industry — is that the raw material cannot be bought 

 in an open market, but must be contracted for. Now, in 

 view of the sudden changes which occur, it may be said 

 that no manufacture thus situated is in a safe or a healthy 

 position. 



F 



EDISON'S NEW LABORATORY. 



ROM the Scientific American we have made the follow- 

 ing extracts from a description of Mr. Edison's new 

 laboratory, now being built at Orange, New Jersey : — 



" Not more than half a mile from Mr. Edison's residence 

 are the foundations and rapidly-rising walls of five large 

 buildings, which, when completed and furnished, will con- 

 stitute his laboratory. It will probably be the largest and 

 most complete private laboratory in the world. Orders 

 have been placed for the physical and chemical apparatus 

 with the best makers in America and Europe. The finest 

 machinery for all uses has been ordered, and will soon be in 

 place. No purely historic apparatus or machinery has been 

 purchased. Everything will be on a practical basis. The 

 range of the laboratory will be extremely wide and diversi- 

 fied. Any experiment relating to anything of which we have 

 any knowledge may here be tried speedily and with all 

 possible precision. The laboratory is exclusively for Mr. 

 Edison's own use, and will be wholly applied to perfecting 

 his inventions and putting them in commercial form. 



"The main building of the laboratory is 250 feet long, 

 50 feet wide, and two stories high. It will contain on the 

 lower floor a complete machine-shop, and upon the second 

 floor of the main building there will be a grinding and 

 polishing department. Upon this floor there will also be a 

 room devoted to photography, another devoted to drawing, 

 and another to machinery and instruments of precision. 

 There will be three experiment-rooms, in which apparatus 

 made in other parts of the laboratory will be experimented 

 with and perfected. Upon this floor the power will be dis- 

 tributed by electricity, a motor being placed at each machine. 

 In each experiment-room there will be a table provided with 

 pipes for supplying city gas, fuel gas, compressed air, cold 



