472 



NA TURE 



[March i6, 1899 



the principal points to be considered were weight and space 

 required, economy and durability. On account of the last two 

 considerations, boilers of the large-lube type had been adopted 

 for the larger vessels. The Belleville boiler was fitted in these 

 vessels, and in recent cases these had been fitted with econo- 

 misers, the number of tubes in the generators being reduced. 

 Trials on shore showed 1 2 to 15 per cent, increase of economy 

 due to the use of these economisers. In the smaller fast vessels, 

 to reduce weight, boilers of the small-tube type were generally 

 fitted. Experience had shown that the ordinary life of the tubes 

 of the Belleville boiler, under ordinary circumstances, would be 

 not less than two commissions. In small-tube boilers this life 

 would generally be much less. Zinc slabs, though still of use 

 in arresting corrosion, could not from the nature of construction 

 of water-lube boilers be so effective as in water- tank boilers. 

 The parts of the boiler near the feed-water inlet appeared to be 

 very subject lo corrosion, and this appeared to be due to the 

 liberation of air and other gases from the feed-water at this 

 pari. It was endeavoured lo minimise this action by using dis- 

 tilled water whenever possible. 



Mr. E. F. J. Love has drawn up, for the Sydney session of 

 the Australian Association for the .Advancement of Science, a 

 report on our knowledge of the thermodynamics of the voltaic 

 cell. In it the author shows how the general laws of thermo- 

 dynamics have been applied to the determination of electro- 

 motive force, Helmholtz's law, the Peltier effect, dissociation, 

 the calculation of the free energy of the current, polarisation, 

 and the relation between electromotive force and external 

 pressure. It is pointed out that the results here exhibited as 

 deductions from the laws of thermodynamics can in some cases 

 be obtained independently by totally different methods. 



A.N extremely interesting and suggestive memoir, dealing with 

 some investigations on the bacterial diseases of plants, has 

 been contributed by M. fimile Laurent to the Annaks de 

 rinslilul Pasteur. The majority of the experiments were 

 made with potatoes, cultivating them on soil variously treated 

 with manures, chemical and other, and then inoculating the 

 tubercles with a certain micro-organism closely allied to the 

 B. icli communis obtained from the air during the course of 

 the investigations. Different kinds of potatoes were selected, 

 and, as was to be expected, the various chemical manures em- 

 ployed affected the luxuriance of the growth very differently ; 

 but the chief interest of these experiments lies in the fact that 

 apparently susceptibility to bacterial infection varies not only 

 with the variety of potato, but also according to its conditions 

 of cultivation. Thus the bacterial susceptibility of several 

 varieties was increased by their being grown on land liberally 

 treated with lime. According 10 M. Laurent, speaking generally, 

 lime added to soil increases the susceptibility of potatoes to 

 bacterial infection, and nitrogenous and potash manures have 

 the same effect, only to a less extent ; whilst the addition of 

 phosphates distinctly diminishes this susceptibility, as also does 

 common salt, only not so markedly. Some interesting experi- 

 ments are recorded, showing how the virulence of this bacillus 

 towards potatoes can be artificially increased by suitable con- 

 ditions of cultivation. Incidentally, we are told that the typhoid 

 bacillus attacks potatoes with extraordinary energy if the re- 

 sistance of the latter has been reduced by treatment with an 

 alkaline solution ; this activity of the typhoid bacillus being 

 more marked than was the case with other varieties of bacteria 

 which had had a far longer training. The memoir is replete 

 with suggestive work, and affords a fresh outlet for the energies 

 of those bacteriologists who care to study the micro-organisms 

 n their relation lo plant-life. 



The February number of the Quarterly Journal of Miero- 

 icopiail Sdenee is almost entirely devoted 10 Dr. Arthur 

 NO. 1533, VOL. 59] 



Dendy's very interesting memoir on ihe development of the 

 Tuatara (Sphenodon punctatus). 



Mes.srs. Williams and Norgate have just issued No. 70 

 of their Book Circular (Scientific Series), in which is to be found 

 notes on, and the titles of, numerous new and forthcoming pub- 

 lications in all branches of science. 



We are glad to learn that owing to the fact that the circula- 

 tion of Science Abstracts now exceeds 4000 copies monthly, the 

 price is to be reduced from three to two shillings per copy. Mr. 

 W. R. Cooper has been promoted from assistant editor to 

 editor, and the Abstracts are now published by Messrs. E. and 

 F. N. Spon. 



"Ynv. Journal of Applied Microscopy, published monthly by 

 the Bausch and Lomb Optical Company, Rochester, N.V. , has 

 now entered on the second year of its existence, and continues 

 to supply useful practical notes to microscopists on micro- 

 technique, the preparation of microscopical objects, and other 

 kindred subjects. 



From the Michigan State Agricultural College, we have re- 

 ceived Bulletins Nos. 164 and 165 of the Farm Department : — 

 Methods and results of tillage, and draft of farm implements, 

 by M. W. Fulton ; also Bulletins Nos. 5 and 6 of the Botanical 

 Department : — Branches of sugar-maple and beech as seen in 

 winter ; and potatoes, ruta-bagas, and onions, by W. J. Beal. 



Some hydroids collected in Puget Sound are described and 

 illustrated by Mr. G. N. Calkins in the Proceedings of the 

 Boston Society of Natural History. The area examined was 

 comparatively small, two points — Port Townsend and Bremer- 

 ton — being the only localities represented in the collection. 

 These two places, however, yielded no less than thirty species, 

 a fact which promises well for the further investigation at 

 different points on the Sound. 



An addition (No. 24) to the series of " Museum Handbooks," 

 published in connection with the Museum of Owens College, 

 Manchester, has been made by the publication of reprints from 

 the fournal of Conchology of papers by Messrs. J. Cosmo 

 Melville and Robert Standen, on the marine mollusca of 

 Madras, and on marine shells from Lively Island, Falklands. 

 This handbook is illustrated by two plates, one of which 

 consists of a photographic reproduction of Trophon gcversianus, 

 from a specimen in the possession of Mr. Cosmo Melville. 



Lord Dklamere, during his recent expedition into East 

 Equatorial Africa, made a valuable collection of zoological 

 specimens, some of which he is presenting to the Natural 

 History Museum. He succeeded in taking a series of photo- 

 graphs of most of the representative animals met with, in- 

 cluding elephants, girafies, zebras, antelopes, gazelles, &c. As 

 the pictures show the characters of the country as well as the 

 natural features and positions of the animals in their wild state, 

 theyareof scientific interest. They will be included in a volume 

 entitled "Great and Small Game of Africa," to be published 

 shortly by Mr. Rowland Ward. 



In the February number of the Bulletin de la SociM 

 d' Encouragement pour f Industrie Xationaie is an interesting 

 summary by Prof. Grehant of his researches on the products 

 of combustion of lighting gas under different conditions. He 

 has specially .studied the formation of carbon monoxide, on 

 account of the deleterious action upon the health of small traces 

 of this poisonous gas. Two methods were independently em- 

 ployed for this purpose, one physiological, depending upon 

 the analysis of the gas extracted from the blood of animals 

 who had been breathing the vitiated air, and the other purely 

 chemical, depending upon the reduction of iodic anhydride at 



