45^ 



NATURE 



[February 7, 191: 



This increase, as well as the disappearance of 

 Brownian motion, proves that flocculation is due to an 

 increase in the size of the particles. With acids as 

 flocculants, definite combination between them and the 

 kaolin occurs, the acid being almost completely re- 

 moved from the solution up to the point when floccu- 

 lation is complete, beyond which no more is removed. 

 The acids being in a highly hydrated condition accounts 

 for the increase in volume of the kaolin particles on 

 uniting with them. With alkalis the phenomena are 

 the same, but combination is complete only in the pre- 

 sence of excess of alkali ; hence the concentration at 

 which flocculation occurs is much higher. In verv 

 weak alkaline solutions where there is but little actual 

 combination, the subsidence of the particles is retarded 

 by the attraction of the alkali present, — Dr. J, Aitken : 

 Revolving fluid in the atmosphere. The paper deals 

 with the objections to the cyclonic theory of circulation 

 recently advanced by Sir Napier Shaw. These objec- 

 tions are founded on the fact that the charts of isobars 

 and winds of the weather maps nowhere show a circu- 

 lation such as would be given by a combination of the 

 motions of rotation and translation. It is oointed out 

 that these objections are based on suppositions which 

 do not find support in Nature. If the cyclone were a 

 closed system, the winds would be such as Sir Napier 

 says they ought to be, but as the cyclone is an open 

 one and draws in air at its lower end, and as this 

 incoming air is only on its way to become part of the 

 system, it cannot be treated as having the revolution 

 and translation of the cyclone. If the combination of 

 these two motions is to be found anywhere, it will 

 probably be in the higher winds, and even there they 

 will be affected by the general circulation in the system. 

 — Hon. R. J. Strutt : Ultra-violet transparency of the 

 lower atmosphere and its relative poverty in ozone, 

 (i) The lower atmosphere is found to be comparativelv 

 transparent to ultra-violet light. The A 2536 can be 

 detected on the spectrum of a mercury lamp four miles 

 distant. (2) The solar spectrurn, even when observed 

 from high altitudes when the equivalent thickness of 

 air overhead (reduced to N.T.P.) is less than four 

 miles, is limited by atmospheric absorption to A 2922. 

 Air near the ground-level is therefore much more trans- 

 parent to ultra-violet light than the upper air. (3) 

 Since the limitation of the solar spectrum is almost 

 certainly due to ozone, it follows that there must be 

 much more ozone in the upper air than in the lower. 

 (4) Scattering by small particles acts in the same way 

 as ozone to absorb ultra-violet radiation from a distant 

 source, and this action makes quantitative estimation 

 difficult. ^ Even if the observed enfeeblement of A 2536 

 were entirely due to ozone, 027 mm. of pure ozone 

 in four miles of air would suffice to produce it. Taking 

 scattering into account, the quantity is probably much 

 less, and there is no evidence from this investigation 

 that any ozone is present in the lower air.^ — Prof. A. 

 Fowler : The presence in the solar spectrum of the 

 water-vapour band A 3064. The band at A 3064, which 

 is usually attributed to water-vapour, is quite strongly 

 represented in the solar spectrum, and accounts for 

 at least i<o lines which were previously unidentified. — 

 Prof. A. Fowler and C. C. L. "Gregory :"The ultra-violet 

 band of ammonia and its occurrence in the solar spec- 

 trum. The ammonia band having its greatest inten- 

 sity at A 3360 has been photographed with high resolv- 

 ing power, and the positions of 260 component lines 

 have been determined. In the principal maximum, 

 and in a secondary maximum at A 3371, the band lines 

 are verv closely crowded and form series of the usual 

 type. On the less refrangible side the principal lines 

 form three spries which coalesce and fade out at A 3450, 

 and there is a similar set of three series on the more 

 NO. 2519. VOL. 100] 



refrangible side which coalesce and disappear at A 3287. 

 These two groups, however, are not symmetrical, and 

 they differ considerably from the more usual type of 

 series. It is shown that the ammonia band lines are 

 consistently represented in the solar spectrum and 

 account for about 140 faint lines which were previously 

 unidentified. The remaining band lines are either too 

 weak to appear in the sun or are obscured by lines of 

 metallic origin. The brightest part of the arrimonia 

 band accounts for the greater part of Group P of the 

 solar spectrum. 



Geological Society, January 23. — Dr. Alfred Harker, 

 president, in the chair.— Prof. VV. J. Sollas : A flaked 

 flint from the Red Crag. The remarkable specimen 

 forming the subject of the paper was obtained by Mr. 

 Reid Moir from the base of the Red Crag exposed in 

 the brick-pit worked by Messrs. Bolton and Co. near 

 Ipswich. It is a fragment of a nodule of chalk-flint, 

 irregularly rhombic in outline, with a nearly flat base 

 and a rounded upper surface which retains the whitish 

 weathered crust of the original nodule. The base was 

 formed by a natural fracture which exposes the fresh 

 flint bordered by its weathered crust. Both upper and 

 under surfaces of the specimen are scored with 

 scratches which are mainly straight, but in some cases 

 curvilinear. Two adjacent sides have been flaked by 

 a force acting from below upwards, in a manner that 

 recalls Aurignacian or Neolithic workmanship. The 

 two edges in which the flaked faces meet the base are 

 marked by irregular minute and secondary chipping, 

 such as might be produced by use. On the hypo- 

 thesis that the flint has been flaked by design, these 

 edges should correspond with the "surface d'utilisa- 

 tion " of M. Rutot, and one would expect to find on the 

 opposite edges of the flint the "surface d'accommoda- 

 tion," as, in fact, is the case. The origin of the flaking 

 is discussed, and the author, while admitting that the 

 fashioning of the flint is not inconsistent with intelli- 

 gent design, concludes that the evidence is not suffi- 

 cient to establish this beyond dispute. 



Manchester. 



Literary and Philosophical Society, January 22. — Prof. 

 S. J. Hickson, vice-president, in the chair. — J. W. 

 Jackson : The association of facetted pebbles with 

 Glacial deposits. The object of the paper was to 

 place on record several recent discoveries of facetted 

 and wind-etched pebbles in localities near Manchester 

 and in the Wirral peninsula, and to discuss the asso- 

 ciation of such oebbles with Glacial deposits. The 

 pebbles are of Glacial origin, and all show the char- 

 acteristic features of wind-erosion. The most note- 

 worthy feature, however, is the large number of split 

 and fractured pebbles, all of which exhibit the action 

 of sand-blast on the fractured surfaces, in addition to 

 other parts of the pebble. All stages towards the 

 formation of typical " Dreikanter " are exhibited. The 

 splitting appears to have been independent of rock 

 composition, as both igneous and sedimentary rocks 

 are represented in the series; in the latter they are 

 mainly split along joint-planes. The mode of occur- 

 rence shows that the pebbles were acted on by sand- 

 blast after the deposition of the Glacial beds on which 

 they lay, and in this respect they agree with similar 

 pebbles found in North Germany and in North 

 America. It is suggested that the splitting is due to 

 frost action, and that it is somewhat earlier than the 

 wind-erosion. — The late E. Halkyard (paper edited and 

 revised by E. Heron-Allen and A. Earland) : The fossil 

 Foraminifera of the Blue Marl, Cote des Basques, 

 Biarritz. The Blue Marl of Biarritz forms a cliff 

 stretching for nearly three-quarters of a mile N.N.E. 



