April 23. 1896] 



NATURE 



585 



him of the method of destroying ticks on the cattle of Texas, 

 and, as the study of the tick pest is one of his principal duties, 

 this description is of great value. After several unsuccessful 

 atiempts to destroy the pest by various means, the dipping 

 process has been adopted at Texas with very gratifying results. 

 A large vat of five thousand gallons capacity is used, and the 

 cattle are forced to swim through it. Various carbolic and 

 arsenical sheep-dips were employed as solutions in the vat, but 

 the results were not satisfactory ; either the cattle had to be kept 

 in the dips for too long a time in order to kill all the ticks, or 

 they were irritated by the solutions. This led Dr. Francis to 

 try the eftect of oil in destroying the ticks. It is well known 

 that grease or oil, of almost any kind, is fatal to insects, lice, 

 iVc. , and known facts as to the life-history and structure of ticks 

 gave presumptive evidence that oil might be successfully substi- 

 tuted for the various commercial dips which had been employed. 

 A layer, from three-quarters to one inch in thickness, of crude 

 cotton-seed oil on the water in the vat was first used, the cattle 

 being forced to swim through the vat, so that when they emerged 

 they were covered perfectly with oil. This had no apparent 

 effect on the cattle, but was found to be exceedingly fatal to the 

 tick, and was very much superior to any other treatment tried. 

 Dips of different nature were experimented with, but none as 

 yet used have given such satisfactory results as the cotton-seed 

 oil. Kerosene emulsion was found to have no practical value ; 

 crude petroleum irritates the skin, and emulsifies with water ; 

 resin oil is useless for the purpose ; corrosive sublimate is too 

 dangerous and is not very fatal to ticks even in solution i : 250 in 

 water ; and tobacco sheep-dips have no practical value. Dr. Francis 

 is at present studying the effects of other oils, the most promising 

 being West Virginia Black, a mineral oil. A full description of 

 the construction of the vat and pen enclosure used will be found 

 in the Texas Farm and Ranch of March 14. 



Carnation-lovers will read with mnch interest a Bulletin 

 just issued from the Agricultural Experiment Station of Purdue 

 University. It is entitled " Bacteriosis of Carnations," and 

 describes in great detail an elaborate investigation which Messrs. 

 Arthur and Bolley have carried out on a disease with which 

 carnations are very frequently afflicted. That this disease is 

 caused by tnie parasitic bacteria, these researches appear to 

 prove beyond doubt, and Messrs. Arthur and Bolley have suc- 

 ceeded in isolating the specific microbe, which they have named 

 " Bacterium Dianthi." Although this bacillus grows readily 

 in artificial culture media when rendered acid, producing a 

 yellow pigment, it has only been found in nature in leaves of 

 the carnation-pink, and infection experiments seem to indicate 

 that it is parasitic only upon pinks, and produces no effect on the 

 shoots, leaves, or tubers of potatoes, or on other non-caryo- 

 phyllaceous plants. The disease seems to be started by these 

 bacteria entering the plant from the air through the stomata, or 

 occasionally by means of punctures made by aphides ; whilst 

 their passage from one cell to another is due, in the opinion of 

 the authors, to the secretion of an enzyme, by means of which the 

 microbe "dissolves for itself a passage-way." Although no 

 varieties of carnation are exempt from the disease, yet they 

 differ greatly in their susceptibility towards it. Delicate 

 ieiies and poorly -grown plants are more readily affecied than 

 iious and well-grown varieties. It is satisfactory to learn 

 ili.ii such a simple precaution as keeping the foliage dry, and 

 preventing the presence of aphides, may practically banish this 

 liisease from our carnation-houses. 



A CORRESPONDENT of the Times says : — " Within the last 



weeks there has been in connection with the Dover Coal- 



1 a transition from the experimental to the practical stage. 



he last week of March the Kent Coalfields Syndicate was 



NO. 1382, VOL. 53] 



formed, the capital of which was fixed at ;^2CX3,ooo, and last 

 week the whole of that capital was subscribed, a board of 

 directors chosen, and a contract entered into for the sinking of 

 two shafts as near as practicable to the Shakespeare's Cliff 

 boring, it being stipulated that these two shafts are to be carried 

 down to 2 ft. 6 in. seam ( 1 138 ft.) within eighteen months, and 

 equipped with the most approved machinery capable of winding 

 2500 tons per day." 



A " RECORD " has been accomplished in measuring geodetic 

 base lines by the Swedish surveyor Jaderin. The French staff 

 officers, using double bars of two metals and microscopes, con- 

 sider 400 metres per day good work. Hatt, in Corsica, using an 

 encased steel [ribbon 20 metres long, stretched on stands by two 

 weights of 8 kilogrammes, advanced 500 to 600 metres per day. 

 But Jaderin, by employing successively two wires, one of steel 

 and the other of bronze, stretched by spring dynamometers at a 

 tension of 10 kilogrammes, and supported on ten tripods, suc- 

 ceeded in measuringqup to 3 kilometres in one summer-day — 

 whether at midsummer, north of the Arctic Circle, we cannot say. 

 From the notice which appears in the current number of the 

 Physical Society s Abstracts, we learn that Jaderin's paper has not 

 been printed. 



In a valuable paper [Atti e Memorie della R. Accad. diScienze 

 in Padova, vol. xii., 1896, pp. 89-97), I'rof. G. Vicentini has 

 presented an interesting summary of his investigations on 

 earthquake pulsations. The instrument employed is the micro- 

 seismograph designed by himself (see Nature, vol. li. p. 540), 

 and now erected in the Universities of Siena and Padua. The 

 motion of the paper on which the pulsations are recorded is 

 unusually rapid, and this has allowed a detailed examination of 

 their nature to be made. Prof. Vicentini distinguishes, as a 

 rule, three phases in each disturbance. The first consists of 

 rapid vibrations and small oscillations ; the second of large, and 

 more or less irregular oscillations, with several maxima which 

 begin and end abruptly ; in the third phase the pulsations be- 

 come more regular, and are longer in period. Throughout 

 nearly the whole movement, but especially during the last two 

 phases, the mean position of the pendulum generally undergoes 

 a continuous change, showing that with the more rapid oscilla- 

 tions there coexist long, slow waves with a period of at least 

 twenty seconds, which result in a gentle tilting of the surface of 

 the ground. If the earthquake is a severe one, and the origin 

 at a great distance from the place of observation, the three 

 phases are separated from one another. But, as the distance of 

 the epicentre diminishes, the first two phases partly coalesce, and 

 the rapid vibrations are superposed on the earlier long-period 

 oscillations. When the earthquakes are weak and of local 

 origin, the tilting of the ground is still observed. During the 

 slight Rovigo earthquake of May 25, 1895, for instance, the 

 tilting at Padua took place nearly in a straight line, slowly in 

 the first ten seconds, but more rapidly in the next twelve, when 

 it reached a maximum of about 6". After this, for ten seconds, 

 an equally rapid tilt took place in the opposite direction, and 

 this was succeeded by several smaller oscillations, of about 

 twenty seconds each, before the motion became imperceptible. 



From the Horticultural Department of the Cornell University 

 Agricultural Experiment Station we have a "Geological History 

 of the Chautauqua Grape Belt," a narrow plain in the State of 

 New York, extending north-eastward from the Pennsylvanian 

 State line, bounded on the north by Lake Erie, and south by a 

 high range of hills, well adapted ior the culture of the vine. 



The Department of Entomology of the U.S. Department of 

 •Vgriculture has issued an account of the San Jose Scale, its 

 occurrences in the United States, and the remedies to be used 

 against it, by Mr. L. O. Howard and Mr. C. L, Marlatt. As- 



