September 28, 1906.] 



SCIENCE. 



409 



atoms of hydrogen liberated in the same time 

 divided by the ' valency ' of the element as com- 

 pared with hydrogen. This law was discovered 

 by Faraday; and appears to be precisely true: 

 and inasmuch as the relative weight of every 

 element is known with fair accuracy, it is easy to 

 calculate what weight of substance any given cur- 

 rent will deposit or set free in an hour, if we 

 once determine it experimentally for any one sub- 

 stance. 



By this means, we succeeded in properly 

 adapting the sizes of the generating and other 

 apparatus. All connections were made in a 

 manner to insure a uniform voltage of the 

 various parts of the condenser to prevent 

 local action, each connection being so made 

 and provided with such measuring instru- 

 ments as to insure ready adjustment to effect 

 this. The apparatus was designed in accord- 

 ance with the above statements. Its operation 

 has extended over a period of fourteen months, 

 and with the exception of about ten tubes 

 which have become pitted, the results have 

 been satisfactory. 



When the condenser was planned, the con- 

 denser manufacturer was instructed to slope 

 the tubes down one inch in the direction of 

 flow; but when he did so, it was forgotten 

 that the middle inclination, if parallel to the 

 first and third passes, would then be up-hill 

 for the circulating water, and that when the 

 condenser was shut down all the water would 

 drain out of this middle section except that 

 in the bottom tubes. These bottom tubes it 

 has been found have become somewhat cor- 

 roded, although not seriously. 



The cause for this result having now been 

 found, its prevention has been effected by per- 

 forating the diaphragm in the condenser head 

 to permit prompt drainage of these tubes 

 when the condenser is taken out of active 

 operation. 



The efficiency of the apparatus amply justi- 

 fies the expense of its installation, while its 

 operation is not expensive and the plant here 

 described will now be followed by other pro- 

 tecting plants of the same character. 



W. W. Churchill. 



QUOTATIONS. 



THE NEXT INTERNATIONAL TUBERCULOSIS 

 CONGRESS. 



The International Tuberculosis Congress 

 takes place at intervals of three years, and the 

 latest was held in Paris last autumn. The 

 next, therefore, is due in 1908, and Washing- 

 ton has been selected as the place of meeting. 

 It seems a far cry from now to the autumn 

 of the year after next; but the American 

 National Association for the Study and Pre- 

 vention of Tuberculosis, which has general 

 charge of the arrangements, evidently intends 

 that this meeting shall be notable among con- 

 gresses, and with laudable forethought has 

 already got its plans something more than 

 mapped out. As an initial step it set itself 

 the task of collecting a sum of $100,000 

 towards the expenses, but resolved to get this 

 amount in a fashion quite impossible in any 

 country on this side of the Atlantic. In other 

 words, the minimum subscription was placed 

 not at five shillings but at five thousand dol- 

 lars, in the belief that there would be no diffi- 

 culty in finding at least twenty citizens of the 

 United States ready for such an object to put 

 their hands into their pockets to the tune of 

 £1,000 each. Nor does it appear likely that 

 these rose-colored expectations will be falsi- 

 fied, for about half the sum desired is already 

 in hand. There is a double object, however, 

 in this early collection of the sinews of war. 

 A sum of $100,000 lying at interest at Amer- 

 ican rates for a couple of years will enable 

 another scheme to be fulfilled. This is to 

 award prizes of considerable value to the au- 

 thors of the best papers sent to the congress 

 on certain selected subjects, such as municipal 

 control, bacteriological treatment and sana- 

 toriums, as also to anti-tuberculosis societies 

 which can show the largest increase in mem- 

 bership since the congress of 1905, and to the 

 city, wherever situated, which can claim the 

 greatest improvement in its phthisis mortality 

 rates during a corresponding period. The 

 exact subjects have not yet been finally de- 

 termined, but it is understood that an an- 

 nouncement of them is to be expected before 

 very long, A further novel suggestion which 



