December 22, 1923] 



NATURE 



923 



— H. H. Dixon and N. G. Ball : On the extraction of 

 sap from living leaves by means of compressed air. 

 Branches of Tilia americana and Sambucus nigra were 

 enclosed in a strong cylinder in such a way that their 

 cut ends protruded. Compressed air at pressures up 

 to 20 atmospheres was admitted into the cylinder, and 

 the liquid which exuded from the cut end of the 

 branch was collected. This liquid was found to be 

 completely, or almost completely, free from sugars. 

 Experiments carried out in early and late summer 

 gave similar results. After the leaf cells had been 

 made permeable by means of toluene vapour the 

 sugar in the expressed sap amounted to about 5 per 

 cent. — H. H. Poole : Some experiments on the con- 

 vection of heat in vertical water columns. Experi- 

 ments are described on the convection of heat in 

 single and also in double vertical water columns. In 

 most cases, the flow of heat increases much more 

 rapidly than the temperature gradient. The smaller 

 the column the more rapid is the rise of heat flow with 

 rise of gradient. It is concluded that, for the small 

 gradient existing in the earth the effect of convection 

 in water-logged porous rocks would be negligible. 

 Where, however, water-filled fissures occur, we should 

 expect an appreciable increase in the vertical flow 

 of heat. 



Royal Irish Academy, December 10. — Prof. Sydney 

 Young, president, in the chair. — J. B. Gatenby : Notes 

 on the human ovary, with special reference to the 

 corpus luteum of ovulation. The minute cytology of 

 the lutein cells of the human corpus luteum is de- 

 scribed. There is a Golgi apparatus larger than the 

 nucleus ; the lutein granules are not true fat, but are 

 probably the mitochondria loaded with lipochrome. 

 A new type of cell is described, called the stellate 

 chromophil cell, probably the homologues of the 

 clasmatocytes of areolar connective tissue. Possible 

 cytological criteria for distinguishing between the 

 corpus luteum spurium and verum are given. 



Edinburgh. 



Royal Society, December 3. — James Chumley : 

 Deep-sea deposits of the Atlantic Ocean. This 

 detailed research was based on a large series of 

 deposit-samples (1426 in number) collected from the 

 floor of the Atlantic by thirty-five expeditions between 

 1857 and 191 1, varjdng in latitude from 50° S. to 

 60° N., and in depth from no to more than 4500 

 fathoms. The examination of these materials was in 

 progress at the Challenger Office, Edinburgh, under 

 the superintendence of the late Sir John Murray at 

 the time of his death in 1914. Mr. Chumley, who 

 was associated with Sir John Murray for a number 

 of years as assistant, has finished the descriptions and 

 worked up the results in accordance with the methods 

 established by him. There are detailed descriptions 

 of 1426 samples, which cannot fail to be of signal 

 service in any future oceanographical work in the 

 Atlantic. The descriptions are followed by a discussion 

 of the information furnished as regards (i) the various 

 types of deposits, (2) the distribution of the different 

 constituents entering into the composition of the 

 deposit. 



MaN'CH ESTER. 



Literary and Philosophical Society, December 4. — 

 W. B. Wright : The search for concealed coalfields 

 in the north of Ireland. Valuable areas of unworkcd 

 coal exist beneath the cover of the newer rocks in 

 the counties of Antrim and Tyrone. The structure 

 of the area covered by the newer rocks is controlled 

 by a series of direct and transverse troughs at the 

 intersection of which the deepest basins occur. As 



NO. 2825, VOL. I 12] 



there is a considerable amount of evidence indicating 

 that these basins are more accentuated in the older 

 rocks below than in the overlying cover, they are 

 very likely to contain the coal measures, which form 

 the upper member of the older series. The margin 

 of one of the coalfields so indicated is in fact visible 

 at Coalisland, Co. Tyrone, where the newer rocks 

 have been removed by denudation, and this is now 

 being worked by Sir Samuel Kelly some little distance 

 in from the outcrop. An exceptionally rich series of 

 coals have been penetrated and a large output is 

 confidently predicted. 



Sheffield. 



Society of Glass Technology, November 21. — H. S. 

 Houldsworth : Note on the influence of rapid chilling 

 on the reversible expansion of clay. The phenomena 

 cited are consistent with the explanation that solution 

 of free silica occurs at the higher temperatures of 

 heating, that this separates out as cristobalite or 

 tridymite on slow cooling. It does not so separate 

 on rapid cooling. Some imperfect separation is 

 likely, but not in a sufficiently definite form to be 

 able to exert its proper influence on the expansion 

 phenomena. — P. Marson : Glasshouse pots : some 

 notes on their manufacture and use. The mixing, 

 weathering, and preparation of the clays were 

 described. Pots which have been stored for a long 

 period after drying give more trustworthy results than 

 new pots used shortly after drying. Of faults which 

 develop in the drying room the chief are cracks 

 across the bottoms of the pots and drying cracks along 

 the angles inside. Nine days should be occupied in 

 heating up large pots in the pot arch. After setting, 

 the pot should be left to mature in the furnace for not 

 less than 48 hours before filhng on. — Kurd Endell : 

 The casting process for glasshouse relrac lories iia 

 German glass plants. Tests show that cast pots are 

 denser than hand-made ones. Cast pots are chemic- 

 ally more resistant than hand-made pots, and there 

 is no perceptible difference between them in respect 

 of heat resistance. 



Calcutta. 



Asiatic Society of Bengal, November 7. — N. 

 Annandale : Aquatic gastropods. (Zoological results 

 of the Percy Sladen Trust Expedition to Yunnan in 

 1922.) The most remarkable feature of the water- 

 snails of the province of Yunnan, particularly those 

 of the great lake Erh-hai, is the close resemblance 

 between many of the shells and those of certain 

 tertiary beds in Central Europe. Definite relations 

 exist between these shells and those of the tertiary 

 beds of the Shan plateau, but the resemblance between 

 the Chinese and the European species is due to the 

 convergent evolution. — W. M. Tattersall : Crustacea 

 Amphipoda. (Zoological results of the Percy Sladen 

 Trust Expedition to Yunnan in 1922.) Two speci- 

 mens of Gammarus were collected, G. annandelei 

 recently described from eastern China and Japan, 

 and a new species allied to G. crassus from the Caspian 

 Sea. — R. B. Seymour Sewell : Geographic and 

 ocean ographic research in Indian waters. (i) The 

 geography of the Andaman Sea basin. The basin 

 bounded by the Nicobar- Andaman ridge and the 

 ridge itself are of composite character. A barrier- 

 reet of coral exists on the western side of the ridge. 

 (2) A study of the nature of the sea-bed and of the 

 deep-sea deposits of the Andaman Sea and the Bay 

 of Bengal. Charts are given showing the nature of 

 the deposits at different points, the limits of the 

 deposits of mud brought down by the great rivers, 

 and the influence of currents on the bottom. (3) 

 The density and salinity of the waters of Indian seas. 



