15^ 



NATURE 



IDec. 13, 1 1 



and along the south coast, a wave of less height was 

 experienced 



" The M^cdit, on our passage down from Ashburton Rii'er 

 (when distant from 50 to 100 miles off the west coast of 

 Australia, and about 1000 miles south-south-east of Sunda 

 Strait), was visited by a shower of volcanic dust (in 

 appearance like prepared "fuller's earth"), which fell 

 some time between sunset of August 30 and sunrise of 

 August 31, the wind being oa-shore at the time. 



" If the dust were associated with the disturbances in 

 Sunda Strait of August 27 and 28, it must have travelled 

 1050 miles in three days." 



BICENTENARY OF BACTERIA 



r W^ have received the two following communications 

 L ' on this subject : — Ed.] 



At the present time, when so many anniversaries of 

 great men and great events are celebrated, it seems 

 opportune to reme nber that exactly two centuries have 

 passed since a discovery of the greatest consequence was 

 made in the Netherland's. In a letter dated September 

 14, 16S3, from Delft, to Francis Aston, F.R.S., of London, 

 Antony van Leeuwenhoek gives notice to the Royal 

 Society that willi the aid of his microscope he has dis- 

 covered in the white substance adhering to his teeth very 

 little animals moving in a very lively fashion (" animal- 

 cula admodum exigua jucundissimo rnodo sese moventia." 

 " Arcana natura; detecta," Delft, 1695 : " Experimenta et 

 Contemplationes," p. 42). Tlicy were the first Bacteria 

 the ]nnna>i eye ever saw. Among theni Leeuwenhoek 

 distinguishes several species, the descriptions and draw- 

 ings of which are so correct that \vc may easily recognise 

 them. The rods, with rapid movement penetrating the 

 water like fishes, are Bacilli ; the smaller ones rotating 

 on the top are Bacterium; one undulating species is 

 Vibrio riigula: the parallel threads of unequal length 

 but of equal breadth are Leptotlirix bticcalis : though 

 motionless, they belong to the moving Bncilli. Leeuwen- 

 hoek Avonders how, notwithstanding the scrupulous 

 care with which he cleans his teeth, there could live 

 more animalcula; in his mouth than men in all the 

 provinces of the States-General. Some years later, 

 not perceiving again the movements of the Bacteria 

 between his teeth, he supposes he had killed them by 

 taking hot coffee at breakfast ; but very soon he discovers 

 anew the old species, and the new drawings of Bacillus 

 and Leptothri.v; which he sends to the Royal Society in 

 the middle of September, 1692 {I.e., p. 336) are still more 

 accurate than those of 16S3. They have not been sur- 

 passed till within the last ten years. It deserves oin- 

 highest admiration that the first discoverer of the in- 

 visible world ould already reach a limit which has never 

 been overstepped, though the members of the Royal 

 Society, when considering two hundred years ago the 

 curious communications of the philosopher of Delft, may 

 have scar, ely foreseen that his astonishing discovery had 

 opened to science a new path which only in our own d lys 

 has led to the most important revelations about fer- 

 mentation and disease. Ferdinand Cohn 



Breslau, November 27 



It cannot be a matter of indifterence to English men 

 of science, and especially to the Fellows of the Royal 

 Society, that the bicentenary of the discovery of those 

 immensely important agents of putrefaction, fermenta- 

 tion, and diseise, the Bacteria, is at hand. 



ItWdS to the Royal Society of London that Antony 

 van Leeuwenlioek communicated his discovery, and we 

 may be sure that neither he nor the Koyal So:ietv of that 

 day anticipated the extraordinary interest which would 

 attach itself in two centuries' time to the orjanisins dis- 

 covered by the patient and accurate student of minute 

 life. 



Leeuwenhoek's " discovery " is a remarkable exainple 

 of that unexpected giving of rich gifts to future genera- 

 tions of men «hich marks the progress of scientific re- 

 search in all its branches. It is for the Royal Society to 

 devise some means of celebrating this bicentenary in such 

 a fashion as to use the great interest and even fascination 

 which Bacteria have at this moment for the English 

 public, so as to excite sympathy with pure and unremu- 

 nerative scientifi : research. Antony van Leeuwenhoek is 

 the type of th; single-minded student of living structures. 

 The investigation of the properties and life-history of 

 Bacteria, although commenced by him two hundred years 

 ago, is still in its infancy. Schwann, Pasteur, Lister, Cohn, 

 Nageli,and Koch have broughtus within the last fifty years 

 far beyond Leeuwenhoek's first discovery, but a hundred 

 such men are needed to carry on the work of discovery. 

 Who will employ them ? Are we to wait two centuries 

 more for knowledge about Bacteria which lies, as it were, 

 ready to our hands, waiting to be picked up ? knowledge 

 which will probably save many thousands of lives 

 annually — if we may judge by the results already attained 

 by the discovery of the relation of Bacteria to the sup- 

 puration of wounds and to the production of diseases. 



The Royal Society could not better celebrate the 

 bicentenary of its Dutch correspondent's discovery than 

 by taking steps to urge on the English Government the 

 expenditure of ample funds upon a new and vigorous 

 prosecution of the study of the relations of Bacteria to 

 disease, in fact upon the foundation of a national 

 laboratory of hygiene. L. 



THE UPPER CURRENTS OF THE 

 A TMOSPHERE 



ALL w'inds are caused directly by differences of atmo- 

 spheric pressure, just in the same way that the flow 

 of rivers is caused by differences of level ; the motion of 

 the air and that of the water being equall)- referable to 

 gravitation. The wind blows from a reg on of higher 

 towards a region of lower pressure, or from where there 

 is a surplus to where there is a dehciency of air. Every 

 isobaric map, showing the distribution of the mass of the 

 atmosphere o\er any portion of the earth's surface, in- 

 dicates a disturbance more or less considerable of atmo- 

 spheric equilibrium, together with general moveinents of 

 the atmosphere from regions of high pressure towards 

 and in upon low-pressure areas. All observation shows, 

 further, that the prevailing winds of any region at any 

 season are merely the expression of the atmospheric 

 movements which result from the disturbance of the 

 equilibrium of the atmosphere shown by the isobaric 

 maps as pre\ailing at that season and over that region. 

 All observation shows, in a manner equally clear and 

 uniform, that the wind does not blow directly from the 

 region of high towards that of low pressure, but that, in 

 the northern hemisphere, the region of lowest pressure is 

 to the left hand of the direction towards which the wind 

 blows, and in the southern hemisphere to the right of it. 

 This direction of the wind in respect of the distribution of 

 the pressure is known as Buys Ballot's Law of the Winds, 

 according to which the angle formed by a line drawn to 

 the centre of lowest pressure from the observer's position, 

 and a line drawn in the direction of the wind is not a right 

 angle, but an angle of from 60' to 80'. This law absolutely 

 holds good for all heights up to the greatest height in the 

 atmosphere at which there are a sufficient number of 

 stations for drawing the isobarics for that height ; and 

 the proof from the whole field of observation is so unifonn 

 and complete that it cannot admit of any reasonable 

 doubt that the same law holds good for all heights of the 

 atmosphere. 



In low la' itudes, at great elevations, atmospheric pressure 

 is greater than it is in higher latitudes at the same height, 

 for the obvious reason that owing to the lower temperature 



