298 



NA TURE 



[January 25, 1894 



graphs taken mainly for the purpose of demonstrating the intri- 

 cate folding of the rocks and the varied effects of weathering in 

 those glaciated Alpine areas. The "Atlas" merits a wider 

 circle of admirers than merely the students of geology, for it 

 reveals in the most effective manner the structure of one of the 

 'grandest regions of the Alps, a region which must be familiar 

 to ail English lovers of the Swiss lakes, Grindelwald, and the 

 Rhoue Valley. 



The Electrician of January 19 contains an interesting coloured 

 map showing; the electric-lighting districts of London. Our 

 contemporary says that the chief alteration in the map, as com- 

 pared with the one of last year, is the extension of the city 

 mains. The Chelsea Company has run down the King's Road, 

 but the London Company has followed it, and is in active com- 

 petition. The Metropolitan Company and St. Pancras Vestry 

 have thrown out a branch or two, but the additions to the mains 

 have, on the whole, been made by " drawing in " additional 

 conductors rather than by advance into new streets. In 

 another place we read that the Owens College Physical 

 Laboratory is prepared to test a limited number of electrical 

 instruments free of charge. The testing will be carried out by 

 qualified assistants, the electrical standards will be compared 

 from time to time with those of the Board of Trade, and every 

 effort will be made to ensure accuracy. All enquiries should be 

 addressed to Prof. Arthur Schuster, Owens College, and headed 

 "Physical Laboratory Testing Department.'" 



The recently published report of the Magnetic Observatory 

 of Copenhagen for 1892 contains a description of the work 

 which has been carried on in the " field," as well as tables con- 

 taining the results of the observations made at the observatory. 

 The tables given include the values of the declination, hori- 

 zontal force, and vertical force for every hour for each day of the 

 year (1892) as obtained from the self-recording instruments, the 

 absolute value of the readings having been determined on five 

 or six days in each month. There are also tables giving the 

 diurnal variations which have been derived from measurements 

 made on selected quiet days. Observations made in the island 

 of Bornholm show that there exists considerable magnetic dis- 

 turbance, for while if there were no disturbance the declination 

 would vary between 9° 11' on the east _side and 9° 29' on the 

 west, it is found that at some places on the east shore the de- 

 clination is 11°, and at one spot near the middle of the west 

 shore values as low as 7° have been obtained. Observations 

 which had been made in 1892 showed that the true lines of equal 

 declination were in many cases closed curves, and thus the dis- 

 turbances must extend to the surrounding water. With a view 

 to tracing the isogonals after they leave the land, M. Hammer 

 has made a series of declination observations on a raft which 

 had been made without any iron, and a map showing the 

 isogonals obtained is published in the report. The greater part of 

 the island consists of granite containing iron, and a small piece of 

 the rock when brought near the box containing the declination 

 needle is found to give a deflection of from a few minutes to two 

 degrees. A map showing by means of arrows the disturbances 

 in horizontal force, indicates in a very clear and striking manner 

 that there exists a strong centre of force a little to the north of 

 the middle of the island. A special series of observations have 

 enabled the magnetic effect of a number of dykes consisting of 

 diabase 'to be shown and measured, a full account of v/hich will 

 be published in the Bulletin de I'Acadimie Koyale de Danc- 

 mar/c. 



The occurrence of true dropsical diseases of plants, not due 

 to the activity of micro-organisms, has been placed beyond doubt 

 by Mr. G. F. Atkinson, of Cornell University. Such a disease 

 was noticed, as we read in a paper on the subject contributed 

 to Science, in some tomatoes grown in the forcing-houses of 

 NO. 1265, VOL. 49] 



the University. The leaves were strongly curled, and the veins- 

 on the under side were swollen and whitened. The cells in the 

 affected areas were stretched radially to an enormous extent. 

 Finally they burst, giving out a large quantity of water, and 

 leaving elongated, depressed, and blackened areas in various 

 stages of decomposition. Inoculations of healthy plants with 

 cultures from the diseased areas gave no result, and no fungi of 

 ordinary dimensions could be discovered microscopically in the 

 early stages of the trouble. The disease was purely physio- 

 logical, and 'due to the preponderance of root-pressure over 

 transpiration in the moist and warm atmosphere of the forcing - 

 house, the leaves not being able to give out the moisture 

 absorbed by the roots. The disease could be brought on arti- 

 ficially by subjecting healthy plants to pressure. Apple trees 

 subjected to severe pruning during the winter suffered from a 

 similar disease when growth began in the spring. 



The second part of vol. i. of "Contributions from the 

 Botanical Laboratory of the University of Pennsylvania" is 

 entirely occupied by a paper by Dr. J- W. Harshberger, 

 entitled "Maize: a botanical and economic study." After a 

 description of the anatomical and histological characters of Zea 

 Mays, its origin is discussed at length, and this is followed by 

 a treatise on its geographical distribution, and on its agriculture 

 and economic value. The evidence appears to point, beyond a 

 doubt, to the original home of the maize being Central Mexico, 

 and not Asia, as some have supposed. 



The difficulty of satisfactorily differentiating between the 

 typhoid bacillus and its constant companion the B. coli communis 

 still remains, although numerous devices have from time to 

 time been introduced, which have materially assisted in the 

 separate diagnosis of these two bacilli. One of the most recent 

 is that lately described by Dr. Schild {Centralblatt f. Bakterio- 

 logie, vol, xiv. p. 717), and is based upon the greater sensitive- 

 ness exhibited by the typhoid bacillus over the colon bacillus to 

 the action of formalin vapour. Thus, whilst well-developed 

 gelatine-cultures of the typhoid bacillus were destroyed when 

 exposed for seventy-five minutes to the vapour derived from 

 5 c.c. of formalin, the B. coli communis was usually still alive 

 after being similarly treated for two hours. The difference in 

 this respect between these two organisms was still more strik- 

 ingly brought out in their behaviour in broth to which formalin 

 had been added, the typhoid bacillus being unable to grow in 

 the presence of i : 15,000 parts of formalin, whilst the colon 

 bacillus developed vigorously in broth containing i : 3000 parts. 

 In order to turn this characteristic to practical account in the 

 separate identification of the typhoid bacillus, Dr. Schild recom- 

 mends that test-tubes containing 7 c.c. of sterile neutral broth- 

 should each receive o'l c.c of a i per cent, solution of 

 formalin, so that the formalin is present in the proportion of 

 I : 7000 ; the inoculations are then made, and the tubes kept at 

 37° C. If typhoid bacilli are present, the solutions remain 

 quite clear ; but if the colon bacillus has been introduced, 

 turbidity is apparent in twenty-four hours. By this method Dr. 

 Schild states that he was able to separately identify the typhoid 

 and colon bacilli in a sample of well water sent to him from a 

 place where an epidemic of typhoid fever was prevailing. 



A LARGE portion of the Bulletin of the Royal Gardens, Kew, 

 Nos. 82 and 83, is occupied by an interesting report from Dr. 

 King, of Calcutta, of a botanical exploration of the Sikkim- 

 Tibet frontier, undertaken by Mr. G. A. Gammie. Other 

 papers are on " Poling in Agave Plants," " Coffee Cultivation 

 in the New World," and "The Resources of British Honduras. " 



A CATALOGUE has been issued showing the works on natural 

 history, mathematical, and physical sciences, offered for sale by 

 Mr. Bernard Quaritch. 



