March 31, 1898] 



NA TURE 



517 



an infectious disease due to a specific organism. The author's 

 case rests on three lines of argument. He begins by showing that 

 excessive heat does not produce the disease ; stokers, oven- 

 cleaners, miners, and iron-workers are exposed to temperatures 

 higher than those of any known climate, without ever contract- 

 ing the malady. The Assam tea-planters and the closely-shaven 

 Chinese are constantly exposed to the hottest sun, and are 

 equally exempt. Dr. Sambon next discusses the geographical 

 distribution of the disease, and proves that the areas in which it is 

 endemic ar^e strictly defined. It is very common in the low- 

 lying regions of the Eastern United States, between the Appa- 

 lachians and the Atlantic ; it is unknown in Europe ; it extends 

 along the Nile Valley, Red Sea, and Persian Gulf; it prevails 

 in the Indo-Gangetic alluvial plain, but not on the adjacent 

 Indian highlands. Another peculiar feature of the disease ex- 

 plicable on the infection theory is the occurrence of epidemics, 

 which may decimate hospital wards and not affect men exposed 

 to greater heat and sun. Dr. Sambon concludes that the distri- 

 bution, etiology, morbid anatomy, and epidemic character of the 

 <lisease together demonstrate its organic origin. The specific 

 organism has not been detected, but the author believes it lives 

 in the superficial layers of the soil, and is conveyed to the lungs 

 ■or alimentary canal by dust. 



A PRELIMINARY Statement just issued by the Canadian Geo- 

 logical Survey, in advance of the detailed annual report, shows 

 that the gold produced by the Dominion in 1897 amounted to 

 a value of 1,238,000/. This means that the Canadian gold 

 output increased by 1226 per cent, in a single year. In 1896 

 gold only formed 1 2 "30 per cent, of the total mineral produce of 

 the country (reckoning by value), while coal and building 

 material provided 31-94 per cent, and 1572 per cent, respect, 

 ively. In 1897 gold rose to the second place on the list, with a 

 percentage of 21 "50, coal and building material being credited 

 with percentages of 25"3i and 12*50 respectively. 



A SHIP model experiment tank is being built at Washington 

 by the United States Navy, at a cost of about 100,000 dollars. 

 From a description in the New York Engineer, we learn that 

 the tank will be a concrete lined basin, surmounted by a brick 

 building 500 feet long by 50 feet wide, the basin itself being 

 47 feet long by 43 feet wide by 14 feet deep. On each side of 

 the basin, for its whole length, will be iron rails supporting the 

 ends of a carriage spanning the basin, this carriage being pro- 

 pelled along the tank with the model and measuring dyna- 

 mometer attached, the model being guided along while still 

 floating freely in the water. The carriage, with all dependent 

 v)n it, is driven along the tank by four electric motors, taking 

 current from a wire by means of trolley poles. The degree of 

 resistance encountered by the model in passing through the 

 water, also the time taken and the distance traversed, are all 

 recorded diagrammatically and by electrical means. Hydraulic 

 brake cylinders on each side of the carriage provide for stopping 

 the carriage when run at very high speeds. The models ex- 

 perimented with will be one-twentieth of the actual size of the 

 vessels, the model for a 400-foot ship being thus 20 feet long. 

 Tests will be made with models for merchant vessels as well as 

 war-ships, and special experiments will be conducted as to the 

 effects of propellers of different sizes and shapes, and the effects 

 of the shape of the after-end of vessels upon the efficiency of the 

 propeller. 



Mr. J. C. GouDiE contributes the following interesting 

 observations to the February number of the Victorian Natu- 

 ralist, the journal and magazine of the Field Naturalists' Club 

 of Victoria : — " A small species of ant, commonly distributed in 

 the Mallee, has a curious habit of keeping in close confinement 

 a rather large mealy aphis, which feeds on the stems of young 

 eucalypts. Round and over these aphides the ants construct a 



NO. 1483, VOL. 57] 



domed covering of particles of bark, grass, &c. , which serves the 

 double purpose of imprisoning the aphides and excluding other 

 ants. Some of these coverings appear to be entirely closed, 

 while others have an opening left in the edge ; this doorway 

 is, however, constantly guarded by a pair of ants, which con- 

 tinually move about in the open space, and seem much im- 

 pressed with the importance of the duty assigned to them. 

 Each enclosure contains generally from three to a dozen 

 aphides, and about the same number of ants. Upon making 

 a breach in some of these structures, for the purpose of observ- 

 ation, I have noticed that many of the ' live stock ' were imme- 

 diately seized by the ants and forcibly removed to a place of 

 safety. The ant under notice is about a quarter of an inch 

 in length, and is of a uniform dark reddish-brown colour, and 

 forms its ordinary habitation under logs, or in old rotten 

 stumps, and sometimes in the ground. Several other species of 

 ants are very assiduous in their attendance on the various 

 aphides, Tetigonid^, and coccids, but the above is the only 

 kind I have noticed that uses such extraordinary means to secure 

 a monopoly of the much-prized ' honey-dew.' " 



The Journal of the Society of Arts for March 4 contains the 

 account of a lecture, by Captain Baden-Powell, on " Kites," 

 in which the advantages and disadvantages of different forms 

 and combinations of kites, as well as their various uses for 

 lifting, traction, reconnoitring, and other practical purposes are 

 fully discussed. 



KoENiGS and Lie have proved that if the poles are taken of 

 an arbitrary plane with respect to the conies of a Steiner's 

 surface, their locus is another Steiner's surface. A new proof 

 of this theorem is given by Prof. A. Brambilla, in the Rendi- 

 conto of the Naples Academy, who makes use of symbolic 

 notation enabling him to introduce considerable symmetry into 

 the equations. 



Some doubt has existed as to who was the first to discover 

 the microscopic Foraminifera, and to apply the microscope to the 

 investigation of rock-structure. From a communication by 

 Prof Giovanni Capellini to the Rendiconto of the Bologna 

 Academy, it would appear that on March 3, 171 1, a paper, 

 entitled De variis arenis, was communicated to that Academy 

 by Jacopo Bartolomeo Beccari, of Bologna, thus indicating that 

 priority must be awarded to Beccari. 



According to the views communicated to the Bologna 

 Academy by Prof. Federico Delpino, it would appear that 

 the lesser celandine {Ranunculus Ficaria) of our English 

 hedgerows is to be regarded as the dwarf form of a dimorphic 

 plant, whose dimorphism is of the kind known z.% gynodicccism . 

 Prof. Delpino contends that the hermaphrodite form is the 

 larger plant, so common on the Riviera, known as Ficaria 

 callhafolia, and that our Ficaria ranunculoides, Moench, is the 

 smaller female form of the same species. This theory accounts 

 for the facility with which the celandine is propagated agam- 

 ically, and the sterility of its pollen. 



A report on the colour of water by M. Ad. Kemna, of the 

 Antwerp Waterworks Company, has been recently reprinted 

 from the Bulletin de la SociHi beige de Giologie, and is published 

 by Polleunis and Ceuterick, of Brussels. In it the views of 

 various writers, from Arago downwards, on the physical, chem- 

 ical, and organic causes of the different colours of different 

 waters, are summarised, M. Spring's theories being dealt with at 

 considerable length. M, Kemna indicates the practical bearino^ 

 of these investigations on the testing of water supplies of towns , 

 and describes different methods of applying tests. Of these, the 

 tests known as the Hazen tests, and due to Mr. Allen Hazen, of 

 Massachusetts, find most favour with the author. 



