April i8, 1901] 



NA TURE 



587 



LETTER TO THE EDITOR. 



The Editor does not hold himself responsible for opinions eX' 

 pressed by his correspondents. Neither can he undertake 

 to return, or to correspond with the writers of, rejected 

 manuscripts intended for this or any other part of Nature. 

 No notice is taken of anonymous communications.'^ 



Selenium in Sulphuric Acid. 



With reference to the article in Nature on the beer 

 poisoning epidemic (pp. 541-542) as to the possibility of the 

 presence of selenium, either conjointly with or preferentially to 

 some compound of arsenic producing the calamity, the following 

 observations may be of interest. 



Some few years ago, in the course of an investigation on the 

 inertness of the alkaline earths towards hydrochloric acid gas 

 {Ber. Deutsch. Cheni. Ges. xxix. 577-580), I had occasion to use 

 sulphuric acid (labelled puriss) as a dehydrating agent for the 

 gas, but after passage of the gas for some time a red deposit of 

 selenium was invariably observed at the bottom of the Drechsel 

 wash-bottle containing the acid. 



It would, of course, be impossible now to trace the past 

 history of such samples of acid, which might have come from 

 several manufacturers, but these observations may show that 

 selenium is a far more common impurity even in the best 

 samples of acid than hitherto supposed. 



Though some of the ill-informed writers and politicians of to" 

 day might be invited, as a form of hard labour, to obtain sul- 

 phuric or any other acid in a state of purity (credite experto), yet 

 it is not apparent that this acid need be used for the preparation 

 of invert sugar to be subsequently applied to the manufacture of 

 beer. V. H. Veley. 



Oxford, April 6. 



THE BOARD OF TRADE AND ELECTRIC 

 LIGHTING. 



T^HE Board of Trade has been busily engaged during 

 -^ the past few weeks with two inquiries of great im- 

 portance to the electric lighting industry. The decision 

 arrived at in the one of these which dealt with the maxi- 

 mum price to be charged for electric energy has already 

 been referred to in our issue of March 14 (p. 474). The 

 other inquiry, which was opened on March i under the 

 presidency of Sir Courtenay Boyle, occupied the atten- 

 tion of the Board of Trade for six days, and has raised 

 some points of considerable technical and scientific 

 interest. The Board has not, as yet, given its decision, 

 but the hearing of evidence and the pleadings have been 

 completed, and we propose briefly to review the expert 

 evidence in the following article. 



The object of the inquiry was to consider an applica- 

 tion to the Board of Trade, made by various electric 

 lighting companies and local authorities, notably by the 

 Westminster Electric Supply Corporation, for an altera- 

 tion in one of the Board of Trade regulations. The 

 regulation in question provided that " no change should 

 be made in the pressure of the supply to any premises 

 . . . except with the consent of the consumer." This 

 regulation, it will be seen, gives to the consumer the 

 absolute power to veto any change in the standard 

 pressure of the supply to his premises, a change, for 

 example, from 100 volts to 200 volts, which the supply 

 company may desire to make. It was this power of 

 veto that the companies wished to remove, and accord- 

 ingly they made application for an alteration of the 

 regulation by which for the words " with the consent of 

 the consumer " should be substituted the words " on 

 such terms and conditions as may be agreed upon be- 

 tween the undertakers and consumer, or, failing agree- 

 ment, as may be settled by an arbitrator appointed by 

 the Board of Trade," or words to that effect. 



The difficulties which have led to this inquiry have all 



NO. 1642, VOL. 63] 



arisen out of the change from a loo-volt to a 200-volt 

 supply which is being made by the Westminster and 

 other electric light supply companies. The change was 

 started in the case of the Westminster Corporation, 

 which we may take as a typical instance, in 1896, and 

 their reasons for making it were as follows. The system, 

 as originally laid down, was a three wire system with 

 100 volts between each outer conductor and the middle ; 

 by 1895 the demand for electric light had increased so 

 much that the street mains were beginning to get over- 

 loaded, that is to say, the current which they were 

 obliged to carry was more than was economically 

 good. The evil of this overloading was shown in 

 two ways : on account of the heavy current which 

 the mains were carrying the loss of energy in them, 

 which is proportional to the square of the current, was 

 very great, amounting, in fact, to about 12^ per cent, of 

 the total output ; also the drop of voltage in the mains 

 was considerable and made it increasingly difficult to 

 maintain the voltage at the consumer's terminals within 

 the limits of variation allowed by the Board of Trade. 

 In these circumstances, the supply company was faced 

 with a difficulty which could be overcome only in two 

 ways. Either they could put down fresh mains year 

 by year to meet the increasing demand, a proceeding 

 which would involve an expenditure of something like 

 7500/. a year, or they could supply the same amount of 

 energy, using a smaller current and a higher voltage. If 

 the voltage were doubled the same amount of energy 

 would be supplied by only half the current, and the 

 energy loss in the mains would be only one-quarter of its 

 former amount ; the drop of voltage would at the same 

 time be halved (the percentage drop being therefore only 

 one-quarter of its former value), and thus the second diffi- 

 culty referred to above would be avoided. It is perfectly 

 evident, therefore, that from the supply company's point 

 of view the best course to adopt was to increase the 

 standard voltage of the supply. And indirectly, also, this 

 course must be beneficial to the consumers, and prospec- 

 tive consumers, for anything that tends to cheapen the 

 cost of supply to the company tends also to lower the 

 price the consumer has to pay for the energy he uses. 



The consumer has, however, another way in which he 

 can look at thequestinn. It is not simply energy that he 

 wishes to buy, but energy that can be economically con- 

 verted into light ; in fact, he really wants simply to pur- 

 chase light. If, therefore, the 200-volt lamp is less 

 efficient than the loo-volt lamp, it may be to his dis- 

 advantage to have to use energy at 200 volts, even 

 though the cost of such energy may be less. For 

 example, if we may state a similar case, it is not 

 an advantage to a consumer to be obliged to drink 

 arsenical beer, although the cost may be less than that 

 of pure beer. In addition, the change necessitates, in 

 most cases, refitting and rewiring of the premises, since 

 the fittings that are suitable for 100 volts, especially if 

 they are of old patterns, are not good enough for 200 

 volts, and also the wiring is often not good enough for 

 the higher pressure. The question of the liability of the 

 supply company for the costs of these alterations and for 

 the inconvenience caused by the necessity of making 

 them is, however, one which can reasonably be settled 

 by arbitration. The matter of prime importance to the 

 consumer is, we consider, the question of the inferiority 

 — real or alleged — of the light obtained with 2C)o-volt 

 lamps. 



Before the Westminster Corporation decided to make 

 the change, they ascertained to their own satisfaction 

 that the 200-volt lamps were as good as the loo-volt, or, 

 if not as good, so little inferior that the disadvantage was 

 more than counterbalanced by the lowering of the price 

 charged to the consumer. This is a point, however, on 

 which doctors disagree, as was shown by the expert 



