598 



NA TURE 



[April 19, 1906 



black and the lens-shaped thickenings in the coloured part 

 of the film may be seen shooting into the tips of the 

 dendritic growth of solid material. 



The separation of solid matter in a soap film is probably 

 connected with the formation of solid pellicles on the 

 surfaces of aqueous solutions, which has been described by 

 Ramsden, and il supports the theory of churning, advanced 

 bv Agnes Pockels, that the butter separates out in the 

 bubbles formed in the churning process. 



A film which is thinning rapidly owing to rapid evapor- 

 ation often develops a curious " grey pattern " when a 

 considerable amount of black has been formed. This 

 pattern sometimes shows five or six grey stages of thick- 

 ness, and seems to be produced by material spreading out 

 into the film from thickenings which have accumulated 

 during the thinning process. 



It is suggested that the grey pattern, the grains in the 

 black, and the lens-shaped thickenings are formed, like the 

 solid growths in the films, by the concentration of the 

 soap solution. 



February 15. — " The Influence of Increased Barometric 

 Pressure on ".Man. No. I." By Leonard Hill, F.R.S., 

 and M. Greenwood. 



The results of the present investigation show that 



(1) A man can be submitted to a total pressure of seven 

 atmospheres without untoward effects, provided decom- 

 pression be effected gradually, and the capillary circulation 

 be aided by repeated contractions of muscles, joint move- 

 ments, and changes of posture. 



(2) There is no sense of increased barometric pressure 

 so long as the former is constant. 



It is probable 



(1) That the subjective effects of increased pressure, apart 

 from voice changes and lip anaesthesia, depend upon 

 psychical conditions, such as anxiety and excitement. 



(2) The changes in the percentage of carbon dioxide in 

 the alveolar air are conditioned solely by physical vari- 

 ations, and not by any increase or diminution in the re- 

 spiratory metabolism. 



In conclusion, the authors remark that they were unable 

 to find any evidence in support of Snell's opinion (" Com- 

 pressed Air Illness, or so-called Caisson Disease," London, 

 1896, Lewis, p. 212) that the presence of C0 2 in the re- 

 spired air exercises .1 pe< uliarly unfavourable influence under 

 increased pressure. Thus in one experiment the percentage 

 of CO, in the chamber air, at +3 lib., was 062 (equivalent 

 to more than i-S per cent, at +0), and no untoward 

 results occurred on decompression. 



Society of Chemical Industry (London Section), April 2. — 

 Mr. A. G. Salamon in the chair. — Ropiness in flour and 

 bread, its detection and prevention : E. J. Watkins. 

 Breads most frequently attacked by this disease are such 

 as contain bran or low-grade white flours. In the present 

 investigation it has been sought by means of culture ex- 

 periments and the artificial production of ropiness in sound 

 flout to establish the identity of an organism isolated 

 from specimens of ropy bread and flour obtained in 

 England. Cultures made from this bread yielded a small 

 motile bacillus which, after repeated subculturing, was 

 used in a series of experiments made with a known sound 

 flour. Varying proportions of the culture were added to 

 the water used for making dough. Such doughs when 

 fermented showed no sign of bacterial effects, and the 

 bread produced was of normal character when it left the 

 oven. The bread when kept in a moist atmosphere at 

 temperatures of 25 C. to 35 C. became ropy in about 

 twenty-four hours. When the temperature was kept below 

 18° C. the disease did not appear. Dryness of the air 

 generally prevented ropiness even when the temperature 

 was high. Acids exercise a powerful influence in prevent- 

 ing the growth of the bacillus, it being found in a series 

 of tests with varying quantities of acetic acid in the dough 

 that the bread did not become ropy when kept long periods 

 under conditions suitable to the bacillus. The cultural and 

 microscopic characters prove the organism to be Bacillus 

 mesentericus (Fliigge). — The Rose-Herzfeld and sulphuric- 

 acid methods for the determination of the higher alcohols : 

 a criticism : Y. H. Veley. The two methods generally 

 adopted for the determination of the higher alcohols are 

 the Rose-Herzfeld (officially recognised in this country, 



NO. 1903, VOL. J$] 



Germany, and Switzerland) and the sulphuric acid method, 

 adopted in France, consequently practised in this country, 

 and officially used as a general qualitative test for the 

 purity of all kinds of alcohol in Russia. Since these 

 methods give verv divergent results in the hands of 

 differenl analysts, the author records various experiments 

 to determine the accuracy or otherwise of the processes, 

 and also criticises them. 



Entomological hocietv, April 4. — Mr. C. O. Water- 

 house, vice-president, in the chair. — Specimen of the very 

 rare ant For micoxenus nitidulus, a neuter, found in a nest 

 "I Formica rufa at YVeybridge during the present month: 

 H. St. J. Domsthorpc. — Specimen of Platypsylla 

 castoris, Ritsema, a coleopterous parasite of the beaver, 

 from France : G. C. Champion. — Specimens of a Noctua, 

 believed to correspond to Dr. H. Guard-Knagg's original 

 description of Agrotis helvctina (" Entomologist's Annual," 

 1872) : W. S. Sheldon. — Examples of butterflies taken last 

 year in Majorca showing injury to the wings, caused 

 apparently by the attacks of lizards : A. H. Jones. — An 

 account of the calcara observed on the legs of some 

 Hymenoptera : Rev. F. D. Morice. The calcara were, 

 the author said, quite constant in each species, and useful, 

 therefore, as distinguishing characters, the only hymeno- 

 pteron he had come across without them being the ordinary 

 hive-bee. Kirby and Spence considered that they were 

 used for climbing purposes, but this was unlikely, as the 

 spurs occurred in species which did not climb at all. So 

 far as he had noticed, they were used by members of this 

 order for the purpose of cleaning their antenna. Mr. 

 C. O. Waterhouse said that similar spurs existed in the 

 Trichoptera, though they did not assume beautiful forms 

 as in the Hymenoptera; but as to their uses, he was not 

 aware that any observations had been published or made 

 on the subject. Mr. G. C. Champion remarked that they 

 were also well developed on the hind-legs of some 

 t ul'optera. 



Linnean Society, Apiil 5. — Dr. A. Smith Woodward, 

 F.R.S., vice-president, in the chair. — Some plants new to 

 tin- pre-GIacial flora of Great Britain: Clement Reid. 

 Fifty photographs were exhibited derived from material 

 procured at Pakefield, near Lowestoft. The remains were 

 black, and therefore troublesome to photograph, but the 

 specimens themselves could not long be preserved, as an 

 efflorescence occurred, and they fell to pieces, but experi- 

 ments were now being conducted with the view of per- 

 meating the fruits with paraffin, and so ensuring their 

 preservation. — A second contribution to the flora of Africa : 

 Rubiaceae, and Composite part ii. : S. Moore. In a 

 former memoir composite plants were alone dealt with. 

 In the present paper are submitted descriptions of Rubiaceae 

 as well as of Composita?. To the former natural order 

 twelve new additions are proposed, referable to the follow- 

 ing genera : — Otomeria, Oldenlandia, Heinsia, two species 

 of Tarenna, Randia, Tricalysia, Polysphaeria, and two 

 species each of Canthium and Diodia. The Compositae 

 regarded as new number fifteen, of which Helichrysum 

 claims six species; Vernonia, Inula, and Senecio two each, 

 and Felicia, Bidens, and Dicoma one each. — The structure 

 of the stem and leaf of Nuytsia fioribunda, R. Br. : E. J. 

 Schwartz, Nuytsia fioribunda is a member of the 

 Loranthaceae and a native of West Australia, and, unlike 

 other members of this order, it is non-parasitical and a 

 tree attaining a height of some 30 feet. — Taiwanites, a 

 new genus of Conifera? from the Island of Formosa : B. 

 Hayata. Dr. Masters considers the genus a valid one, 

 judging from a small scrap which he had received from 

 the author, who believed his new genus to be intermediate 

 between Cryptomeria and Cunninghamia ■ he himself 

 pointed out that it combined the foliage of Athrotaxis 

 with the cone of Tsuga ; in any case it is a very interest- 

 ing genus. 



Royal Astro" omical Society, April 11. — Mr. W. II. Maw, 

 president, in the chair. — Explanation of the apparent 

 secular acceleration of the earth's orbital motion : P. H. 

 Cowell. The author had found that certain arbitrary 

 assumptions with regard to the sun and moon satisfied the 

 conditions of six ancient solar eclipses. He concluded that 

 ii wis wrong to assign an arbitrary secular acceleration 

 to the moon and none to the sun, and to justify this by 



