^.o 



SCIENTIFIC NEV^S. 



[April 1st, if 



on a prolonged research into the methods of eliminating 

 them. Their account is given in the " Comptus Rendus " 

 103, 1886, p. 853. The use of tannin they found beneficial, 

 and nitrate of bismuth proved a success, laboratory 

 tests showing that the harmful microbes could be entirely 

 destroyed by this salt. Larger and very valuable experi- 

 ments were then made at the important distilleries of Lement 

 at Bordeaux, and of Bernard and Tilloy at Courrieres. 

 When one ten-thousandth part of nitrate of bismuth was 

 added to the fermenting liquor, the fermentation proceeded 

 \vith remarkable regularity, and there was always a gain in 

 the yield of alcohol of from two to twelve per cent. The 

 advantage of this method was confirmed by parallel tests 

 without the addition of bismuth. 



The Bleaching of Paper and Linen Yarns is being 

 tried in France, by a new process which is about to be intro- 

 duced into this country. If successful it will very materi- 

 ally affect the manufacture of bleaching powder and similar 

 compounds. M. Hermite, the inventor, has found that 

 when a solution of magnesium chloride is electrolysed by a 

 powerful electric current, a compound is formed similar in 

 properties to bleaching powder, and it can be produced 

 at a much cheaper rate. The advantages claimed by the 

 inventor and patentees for their product are rapidity of 

 action and small expenditure in production after the initial 

 cost of plant. The new system has been found to answer 

 admirably for the bleaching of flax yarn, and similar good 

 results have been obtained with paper pulp. The bleach- 

 ing efficiency of the liquid is said to be greater than that of 

 a solution of bleaching powder of the same strength, and 

 the bleaching action is completed in a much shorter time 

 than in the old process. The cost of production is estimated 

 at about JC2 los. for a quantity of material which would do 

 the work of one ton of bleaching powder. The present 

 price of the latter is now _;^8 los., so that the new process 

 should rapidly come into general use in those industries in 

 which rapid and economic bleaching on a large scale is 

 required. 



Rules for identifying Electrical Conductors. — Many 

 troubles and annoyances would doubtless be avoided if 

 certain conventional rules were universally adopted in the 

 fixing of electrical conductors. At present there is seldom 

 any difference in the colour of the positive and negative 

 wires, nor is any fixed rule followed in laying them, and 

 frequently it is most troublesome to find out which is 

 which. It is especially difficult for amateurs or the 

 inexperienced users of electricity. With this in view, our 

 contemporary La Nature calls attention to the following 

 useful rules, which it is suggested should be universally 

 adopted : — 



1 . All positive wires to be placed to the left of, and above 

 the negative wires. 



2. All negative wires to be placed to the right of, and 

 below the positive wires. 



3. All positive wires to be coloured bright red (as is 

 already done to denote the positive pole of accumulators). 



4. All negative wires to be coloured black. 



It is further suggested that all instruments of measure- 

 ment should have their needles arranged to move from 

 positive to negative, in the same direction as the hands of 

 a watch. If these simple rules were well applied, much 

 time would often be saved, and many mistakes avoided in 

 the coupling up of apparatus. 



Pepperette. — Some months ago the spice grinders 

 throughout England received a letter from a firm in Leghorn 

 offering to supply them, at a low price, with an article which 

 was described as poivrette, or pepperette, for admixture with 

 pepper. After a time this substance came, under the notice 



of the public authorities, but for long the true character of 

 poivrette remained a mystery. Under the microscope it had 

 a close resemblance to pepper in colour, appearance, and 

 cells. It was hard and tasteless and was certainly not 

 pepper, but beyond the fact that it was a dense ligneous 

 substance it baffled the skill of the analysts. The mystery 

 was at last cleared up by Dr. Campbell Brown, public 

 analyst for Lancashire. Reflecting that olives were a home 

 product of Leghorn, he thought the stones might be the 

 adulterant. He had some olive stones ground, and the 

 whole problem was solved. Poivrette was simply ground 

 olive stones. In his certificate produced during some 

 recent prosecutions. Dr. Campbell Brown describes pepper- 

 ette as " a hard, tasteless, woody substance, absolutely worth- 

 less, composed of ground olive stones, imported into this 

 country from Italy and sold at id. per lb. for the express 

 purpose of being used for fraudulently increasing the weight 

 of pepper." Pepper is sold wholesale for about is. 4d. per 

 lb., and it would probably not be an exaggeration to say that 

 a pepper grinder in a considerable way of business intro- 

 ducing 15 per cent, of the poivrette into his manufacture 

 would net j£fi, qoo a year by the adulteration. Prosecutions 

 have been instituted, and they have not been without prac- 

 tical eifect. It is now announced that the manufacture 01 

 poivrette at Leghorn has been discontinued. It has just 

 made its appearance in America, however, and there is an 

 evident desire to open the illegitimate trade in the country 

 that gave birth to the wooden nutmeg. 



The Slag from the Thomas Gilchrist Process for 

 making steel has long been supposed to have valuable 

 properties as a manure. In the Bessemer convertor, 

 there is a lining of lime which, in the process of manu- 

 facturing the steel, takes up a large percentage of 

 phosphorus, in the form of phosphoric acid. Phosphate of 

 lime has been used as an artificial manure, in a variety of 

 forms, with very beneficial results on most lands. It was 

 thought that the basic cinder obtained in the Thomas 

 Gilchrist process might, from its large percentage of lime 

 and phosphoric acid, have a manurial value. Some two or 

 three years ago, experiments in this direction were under- 

 taken in Germany by M. Fleisher and others, and from the 

 data which they obtained, it appeared that under certain 

 conditions basic slag had a very marked influence upon 

 crops grown on soils which had been top dressed with it. 

 It was ground into a very fine powder, and then the acids 

 of the soil were able to dissolve the phosphoric acid which 

 it contained ; and it was then in a condition to be readily 

 assimilated by plants. Attention is again being called 

 to this point in consequence of a series of similar 

 experiments which have been carried out by Dr. Munro, 

 at Downton, for the North Eastern Steel Company, and 

 which fully confirm the earlier experiments of the German 

 investigators. It was thought that probably the slag 

 would be more efficacious if it were first converted into 

 a " superphosphate," in a similar manner to bones ; 

 but Dr. Munro and Mr. Wrightson seem to think that this 

 is unnecessary, if care be taken to have the basic cinder in 

 as pure a state of division as possible. As basic slag is a 

 waste product, and hitherto has had no industrial applica- 

 tion, it ought to be obtainable at a much cheaper rate than 

 the Canadian apatite, coprolites, and bone manures which 

 have until recently been the chief artificial fertilisers used 

 in agriculture. Dr. Griffiths has recently, in papers read 

 before the Chemical Society of London, advocated the use of 

 iron sulphate as a manure, and as basic slag contains a 

 considerable quantity of iron in the same condition of oxi- 

 dation as in ferrous sulphate, it may also have some effect 

 upon the manurial value of the Thomas-Gilchrist slag. 



