July 21, 1910] 



NATURE 



The current number of the Bulletin of the Department 

 of Agriculture, Jamaica (vol. i., No. 3), maintains the high 

 standard set by the two previous issues. Mr. R. Kewstead 

 contributes a valuable article on the ticks and other blood- 

 sucking Arthropoda of Jamaica, describing their life-history 

 and the methods adopted in attempts to exterminate them. 

 It appears that ticks are most prevalent during the dry 

 winter months, and that relatively few are found during 

 the rainy season. .As a rule the ticks infest cattle, but one 

 much dreaded species, Chrysomyia (Compsamyia), attacks 

 man ; a case of myiasis thus produced is mentioned. This 

 tick often passes its larval stages in putrid carcases, and 

 is no doubt kept in check by the scavenger work of the 

 John Crows (Caiharics aura), which remove practically all 

 traces of carrion from man's habitations. From an article 

 by the Hon. H. E. Co.x, it appears that tea is now being 

 successfully grown on the island ; the Cinchona strain is 

 used, and yields a tea of mild character similar to the old 

 China teas and without astringency. There is also a 

 useful history of the economic plants of Jamaica by Mr. 

 Harris. 



The twenty-second annual report of the Agricultural 

 Experiment Station, Lafayette, Indiana, chronicles several 

 important events in the history of the station. The old 

 buildings having proved insufficient, new ones were erected, 

 and were formally opened during the course of the year. 

 Still more important, however, was the provision of further 

 funds, necessitated by the rapidly increasing demand from 

 the farmers of the State for information on the lines of 

 the work already being done. So strong was the demand 

 that the General .\ssembly amended the Smith Act of 

 iqoj, whereby the station annually receives 25,000 dollars, 

 and increased the State subvention to 75,000 dollars 

 annually, to be expended as follows : — 10,000 dollars for 

 the general work of the station, 15,000 dollars for the 

 improvement of the crops and soils of the State, 10,000 

 dollars for the advancement of the dairy interests, 10,000 

 dollars for the advancement of live-stock interests, 5000 

 dollars for the investigation of hog cholera and other 

 diseases, 5000 dollars for poultry problems, and 10,000 

 dollars for extension work ; and the Act concludes : — 

 " Whereas an emergency exists for the immediate taking 

 effect of this .Act the same shall be in effect from and 

 after its passage." The extension work includes the dis- 

 tribution of copiously illustrated bulletins dealing with 

 important problems, a number of which we have also 

 received ; the provision of special trains to carry lecturers 

 through the country, teaching as they go ; attendance at 

 shows, and so on. With such liberal support it is not 

 surprising that much good work is done. 



Mr. Rodert M. Brown contributes an interesting series 

 of diagrams to the Bulletin of the American Geographical 

 Society (p. 107) showing the maximum, minimum, and 

 average levels of the waters of the Mississippi system at 

 five stations — Hannibal, on the Mississippi ; Hermann, 

 on the Missouri ; St. Louis, just below the confluence of 

 the Mississippi and Missouri ; Cairo, on the Ohio ; and 

 Memphis, Tennessee. The varying influence of the 

 different types of rainfall occurring in different parts of 

 the drainage area is very clearlj' shown. 



Mr. H. T. Barnes, Macdonald professor of physics, con- 

 tributes an interesting paper, with excellent illustrations, 

 to the Proceedings of the Undergraduate Society of Applied 

 Science of McGill University, Montreal, on the problems 

 of winter navigation on the river St. Lawrence. Experi- 

 ence shows that, with Lake St. Peter free of ice, a con- 

 tinuous open channel above that point may be safely pre- 

 NO. 2125, VOL. 84] 



dieted, for the river is continually s.. uggling to free itself 

 of its icy burden. Prof. Barnes suggests that it would be 

 quite possible to keep the ice-bridge broken up at the foot 

 of Lake St. Peter and at the Sorel Islands, and that the 

 lake itself could be kept nearly free of ice. One ice-breaker 

 could keep the river clear at the Sorel Islands as well as 

 at Port St. Francis, and this, with one powerful ice-breaker 

 at Quebec, would effectively keep the ship channel open. 

 The ice-problem thus solved, Montreal would inevitably 

 become one of the greatest seaports in the world. 



We have received from the author reprints of two papers 

 bv Mr. E. A. Birge, published in the Transactions of the 

 Wisconsin Academy of Sciences, .Arts, and Letters. In the 

 first Mr. Birge discusses a hitherto unregarded factor in 

 lake temperatures. The heat of the sun is mostly delivered 

 to the surface strata of a lake, and distributed to the depths 

 by various agencies, chief of which is the wind. The 

 efficiency of the wind as a distributing agent is opposed 

 and limited by thermal resistance to mixture offered by 

 the decreased density of the warmed surface water, and 

 Mr. Birge brings forward evidence to show that the 

 effectiveness of this thermal resistance increases as the 

 temperature of the water departs from the temperature of 

 maximum density, and decreases as it approaches 4° C. 

 The second paper contains a review of the evidence adduced 

 by Wedderburn in favour of the existence of temperature 

 seiches in lakes, which leaves the author unconvinced. 



Mr. T. S. Ellis has published a pamphlet on " The 

 Winding Course of the River Wye " (Gloucester ; Bellows, 

 price IS.), in which he expresses his views on the origin 

 of adjacent river-systems. He regards valleys divided by 

 cols at their heads as having originally formed a continuous 

 channel, the two sections becoming separated when main 

 systems tended to develop on either side. He does not 

 seem to appreciate sufKciently the effects of rain, frost, 

 and continual land-slide action in the cutting back of 

 valley-heads, but represents geologists as attributing the 

 removal of cols solely to erosion by the young streams 

 flowing from them. On p. 9 he comes very near to the 

 bold suggestion of Mr. A. W. Rogers, that a winding rock- 

 ravine may record the original meanders of the river in 

 alluvium at a higher level. 



The natur^ of intermetallic compounds is discussed by 

 Dr. T. Slater Price in vol. iii. of the Proceedings of the 

 Birmingham Metallurgical Society, which has made a 

 somewhat belated appearance. The paper in question was 

 read in January, 1909, and contains a list of 120 of these 

 curious compounds, more of which are described every 

 month. Among the laws of their formation, it is claimed 

 that the metals forming a sub-group of the periodic system 

 do not form compounds with each other, and, further, that 

 any particular metal either enters into combination with 

 all the metals of a sub-group or else it does not form 

 compounds with any of them. Those sub-groups in which 

 there is a change from metalloid to metal, as in the case 

 of -As, Sb, Bi, form an exception to the rule. The valencies 

 of the metals in their compounds seldom correspond with 

 the ordinary valencies, only thirty bodies out of the 120 

 enumerated showing this agreement, and of these, twelve 

 are compounds of antimony, which approaches the metal- 

 loids in its characteristics. Among the compounds there 

 are some very remarkable formulae, for which no explana- 

 tion is offered. For example, the formulae NaZn,,, 

 NaCdj, FeZn„ NiCd.„ and AuSb, have a strange appear- 

 ance. Among other summaries of the state of knowledge 

 on particular subjects, there are interesting articles by 

 Mr. -A. H. Hiorns on copper-nickel alloys, and by Prof. 

 Arnold on the testing of metals. 



