594 



NATURE 



[Oct. 1 8, 1888 



sodium is to take place. The preliminary heating takes 

 about half an hour, and the actual distillation about an 

 hour and a half. 



The lid of the crucible, to which is attached the con- 

 densing arrangement consisting of an iron pipe dipping 

 into an iron box, is fixed in the furnace ; it has a convex 

 rim which makes a joint with the grooved top of the 

 crucible, with the assistance of a little powdered lime. 

 The crucibles are raised and lowered by means of 

 hydraulic power, the work of removing a crucible from 

 the furnace and replacing it by another being done with 

 great rapidity. 



The reaction which takes place may be represented by 

 the formula — 



6NaHO + FeC 2 = 2Na. 2 C0 3 + 6H + Fe + 2Na. 



This formula is made up in reality of several taking place 

 pari passu. The main point is that it clearly expresses 

 the final result. It will be observed that no carbonic 

 oxide is given off, and the difficulties already referred to, 

 caused by the presence of that gas, are got rid of. The 

 iron is recovered, and used over and over again by coking 

 it with fresh tar. 



It is unnecessary to refer here to the arrangements for 

 the production of the double chloride of aluminium and 

 its reduction by sodium, as no special novelty is claimed 

 for them. 



Mr. Castner has shown great technical skill in devising 

 the plant used throughout the works, and they are in 

 every way a great advance on anything of the kind 

 attempted before. 



A novel feature is that hydrochloric acid, for the manu- 

 facture of the double chloride, is obtained direct by means 

 of pipes from Messrs. Chance's glass-works, which are 

 contiguous, and the carbonate of soda resulting from 

 the operation in which sodium is produced is similarly 

 conveyed to Messrs. Chance's, to be there purified and 

 crystallized. 



The estimated possible output of these works is stated 

 to be 500 pounds of aluminium and 1500 pounds of sodium 

 per day. The cost of manufacture of aluminium has 

 hitherto been between 30^. and 40.?. per pound. By Castner's 

 process it is stated that it can be produced at 15^. That 

 this is so there is but little reason to doubt ; and it is a 

 substantial and important reduction, which will enable 

 aluminium to be used much more largely than has hitherto 

 been possible. Still, before it can be very largely used, 

 the price will have to be further considerably brought 

 down ; and it is much to be hoped that Mr. Castner's 

 success will stimulate him and others to work with this 

 end in view. 



THE QUEEN'S JUBILEE PRIZE ESS A Y OE 

 THE ROYAL BOTANIC SOCI ETY OF LONDON. 



TDROBABLY the last of the Jubilee productions has 

 ■*■ seen the light by the appearance of an article in 

 the Quarterly Record of the Royal Botanic Society of 

 London for the three months ending March last under the 

 title of " Fifty Years of Economic Botany." The article in 

 question forms the essay to which the Council of the 

 Royal Botanic Society has awarded its gold meial and a 

 purse of fifty guineas. The author is Mr. John W. 

 Ellis, L.R.C.P. It needs only a casual glance to discover 

 how deficient this short essay is, not oniy in consequence 

 of the numerous omissions of very important plants and 

 products, but also on account of the imperfect information 

 given under many of the headings. Thus the writer tells 

 his readers that China grass and rhea are two distinct 

 fibres furnished by allied plants, the former by Ba>hmeria 

 ttivea and the latter by B. tcnacissima, while the fact is 

 that China grass and rhea are one and the same thing, 



B. tenacissima being a synonym of B. ttivea. In a casual 

 reference to " Moong " fibre the author is apparently quite 

 ignorant of the fact that its botanical source is Sacc'harum 

 munja, Roxb. New Zealand flax {Pkormiutn tenax) is 

 introduced under textiles, but why is not apparent, for the 

 author concludes his paragraph as follows — " Not having 

 been introduced during the period to which this essay 

 refers, any further mention of this interesting fibre— for 

 which it has frequently been attempted to find a place in 

 the British market— is unnecessary." Why " gun cotton 

 and its derivatives" should occupy a special chapter it is 

 difficult to say, seeing that this explosive substance is not 

 a direct product of the vegetable kingdom ; the author 

 however apparently looks upon it as a much more 

 important vegetable product than the species of cinchona, 

 the ipecacuanha, coca, jalap, or the multitude of new drugs 

 that have occupied such a prominent place in men's minds 

 for the last twenty years. The success that has attended 

 the acclimatisation of the cinchonas in our Indian 

 possessions, whither they were introduced some twenty or 

 thirty years since, when there was a great fear lest the 

 supply of bark from South America should fail because 

 of the great demand, and the consequent reduction in 

 the price of quinine from a guinea to its present price of 

 two shillings per ounce, are facts of sufficient importance, 

 one would think, to be noted in any record of the progress 

 of useful plants. And the same might also be said with 

 regar J to Erythroxylon Coca, considering to what purpose 

 cocaine is now being put, but the author— a member of 

 the medical profession — has apparently a wholesome dread 

 of drugs, and for once has ignored all consideration of 

 them. He seems to have been content to consult very 

 old books for his facts throughout and to have completely 

 passed over modern authorities ; consequently his state- 

 ments are both antiquated and incorrect. 



The old name of Siphonia elasticd is quoted for the 

 Para rubber plant instead of the now better known name 

 of Hevea brasiliensis. Balata is referred KoSapota MulUri 

 instead of Mimusops globosa, and we read that Mr. 

 Jenman's report on the Balata Forests of British Guiana 

 issued in 1885 " will probably assist in developing 

 a demand for this material," while the fact is th t 

 balata has been going down in the estimation of manu- 

 facturers since that date in consequence of it having been 

 found not to be durable when exposed to the air ; manu- 

 factured articles made from it cracked on the surface, and 

 the inner portion lost its tenacity, so that some manu- 

 facturers have given up its use entirely. The Dika plant 

 of W. Trop. Africa, which has long been identified with 

 the Simarubeous plant {/rvingia Barteri), is referred to 

 under the very old name of Mcuigifera Gabonensis, a 

 genus belonging to the natural order Anacardiacta;. 

 Again carapa or croupee oil of West Africa is said to be 

 obtained from the seeds of Carapa gtiittecnsis and crab 

 oil of British Guiana from Carapa guianensis. These 

 two were combined by Prof. Oliver under C. guyanensis 

 in the " Flora of Tropical Africa" so far back as 1868. 



These are only a few illustrations of the general un- 

 trustworthiness of the essay, the circulation of which, k 

 is hoped, will not be large. 



THE ZODIACAL LIGHT. 



"C^ROM the days of Cassini a connection between the 

 -*- zodiacal light and sun-spots has been suggested. 

 In some recent discussions it is denied. But, so far as 1 

 am able to discover, the long series of observations by 

 Heiss and Weber, extending from 1847 to 1883, afford 

 the first opportunity to attack the question. 



The result is in the diagram before you. The broken 

 line represents Wolfs well-known series of relative sun- 

 spot numbers, the jagged full line the mean elongations 



