32 



NATURE 



[March 2, 191 1 



contains an account of the methods employed in the 

 separation of the actinium and ionium. The ionium was 

 finally obtained mixed with i-8 grams of thorium oxide. 

 The activity of this oxide, due to the ionium it contained, 

 was about 3000 times that of an equal weight of uranium 

 oxide. By counting the a particles from a thin film by 

 the scintillation method, the amount of ionium present 

 with the thorium was found to be equal to the amount 

 in equilibrium with 5-3 milligrams of radium in a radio- 

 active material. The actinium was finally concentrated to 

 about 10 grams of material, which gave a final activity 

 about 20,000 times that of uranium oxide. It was esti- 

 mated that the amount of actinium separated was equiva- 

 lent to the amount in equilibrium with 30 milligrams of 

 radium in a mineral. Special experiments were inadi' to 

 test whether ionium was transformed into helium. The 

 presence of helium was determined by its spectrum, and 

 the volume produced was measured. The investigation 

 showed that helium is produced by ionium as well as bv 

 all other products which emit a rays. — J. A. Gray : The 

 secondary rays produced by ;8 rays. Secondary 7 ravs are 

 produced in different materials by the j8 rays of RaE, the 

 greater in amount, the greater "the atomic weight of the 

 radiator. The 7 radiation observed from a preparation 

 of RaE can be greatly increased by a suitable disposition 

 of the active matter and apparatus. — W. R. Bousfleld 

 and W. Eric Bousfleld : The specific heat of water. The 

 object of this investigation was to obtain a basis curve 

 for the specific heat of water, for comparison with specific- 

 heat curves of aqueous solutions. Former observers, using 

 different methods, have obtained widely varying curves ; 

 thus for the specific heat of water at 80°, in ^terms of the 

 15° calorie, the following figures have been given, showing 

 differences of i per cent. : — Barnes, 1-0014 ; Regnault, 

 i-oo8i ; Liidin, 1-0113. For the values in joules of the 15° 

 calorie the following have been found: — Joule, 4-174; 

 Griffiths, 4-198; Barnes, 4-184. The first part of the 

 present investigation is concerned with the determination 

 of the mechanical equivalent of heat in terms of the mean 

 calorie from 13° to 55°, by a method of continuous-flow 

 calorimetry. Mercury thermometers were used which 

 could be read to 0-005°. An interval of 40° was taken, so 

 that an error of o-oi° would not vitiate the result bv more 

 than I in 4000. Through a Dewar vessel containing about 

 3 litres of water, in which was an electric heater, there 

 was passed a current of water, entering at about 13° and 

 passing out at about 55°. The vessel was immersed in a 

 bath kept at same temperature as contents of vessel. 

 The top of the vessel was closed by a platinum box kept 

 10 higher. The electric heater, and the resistance used 

 m series with it for determining the current by help of 

 a battery of standard cells, were of novel tvpe. Each 

 consisted of a spiral glass tube of small bore, into the 

 ends of which are sealed platinum electrodes. The tube is 

 connected with a thermometer tube, so that the spiral forms 

 a thermometer bulb. By calibrating the resistance against 

 the reading of this thermometer tube, the resistance is 

 accurately known, even when a current is passing This 

 type of resistance enabled the authors to surmount a diffi- 

 culty- apparently never considered by previous investigators. 

 1 hey have found that when a heavy current passes through 

 an ordinary standard resistance, the resistance of the standard 

 depends, not only on temperature, but also upon strength 

 of current. This effect may be conveniently called the 

 thermoid effect. The authors believe a liquid merrurv 

 resistance is free from any such effect. The continuous-flow 

 experiments gave for distilled water j'', =4-182. To get 

 the curve for J from 0° to 80°, a weighed quantitv ^of 



^^l Ir ^^T l^""^^^ ^'"""^ °° *« ^° ^y ^t^ges ^hich gave 

 •J^o J1.1 J^ J55' ^^'^ mean specific heats over the intervals. 

 For this purpose, the capacity of the calorimeter was 

 obtained from the value of jjg previously determined, and 

 a separate research on the specific heat of glass was 

 earned out in order to obtain the variation of capacitv 

 with temperature. From these an equation for the value 

 J* was obtained, and then the value of J from point to 

 point, from the equation 



UK". 



mar 

 sho\ 



NO. 2157, VOL. 86] 



The authors thus obtain 



J =4-2085 — 0-00302 2 (* + o-oooo7833#- — o-oooooo49oS',/ 

 which gives for the value of the 15° calorie 4179. '1 

 resulting curve corresponds closely with that obtained 

 Liidin by the method of mixtures, and differs consideral 

 from that obtained by Barnes by continuous flow w 

 |)latinuni thermometry. — Prof. C. Niven : The 11 -n 

 ment of specific inductive capacity. The paper 

 an account of work undertaken to determine the 

 inductive capacity of liquids by the method of re~' m 

 The frequencies of the discharge of condensers \s 

 and with liquid as dielectric were compared by th- 

 meter and dielectric constants of the liquids 1 

 With some liquids, notably with water, the qui - 

 complicated by the conductivity of the liquid. T! 

 ditions of discharge through a conducting liquid ar 

 fore first determined, and the condition of r<- 

 between the two resonating systems found. This i- 

 to be of a simple character, reducing practically to H'l 

 it would be if the conduction through the liquid tv- 

 neglected. In some cases, water, for example, it 

 impossible to set up oscillations directly, but by inti 

 posing in the circuit of the condenser another of ronsidi 

 able capacity, the oscillations may be obtained, ^^']l< n t 

 capacity of this interposed condenser is relatively v^ 

 large, it has no appreciable effect on the frequency of 

 oscillations produced, which are thus those of the liq 

 condenser alone. Owing to the rapid variation 

 I specific inductive capacity with temperature, 



arrangements had to be made to keep the liquid it 

 I constant temperature while measurements were bei 

 i made. The results of a number of determinations 

 I different temperatures are given for water and alcohol. 



Zoologrical Society, February 7. — Prof. E. A. Minchi 

 vice-president, in the chair.— Dr. W. N. F. WoodlaiM 



Structure and function of the gas-producing mechan; 

 (" red body ") found in connection with the gas-blad(' 

 of many teleostei (Physoclisti and Physostomi). A! 

 summarising some of the principal facts known conct 

 ing these subjects, the author discussed various theoi 

 already advanced to account for the details of gas-prodi 

 tion, and showed that the most satisfactory hypothesis w 

 a combination of the views of Jaeger and of Nusbau 

 and Reis, supplemented by additional facts and sugg< 

 tions then advanced in the paper. — Prof. J. C. Ewar 

 Skulls of oxen from the Roman station at Newstei ' * 

 rose. The author stated that examination of th- ; 

 from Newstead lent support neither to the descent of ; 

 European cattle from the Urus {Bos primigenins) nor 

 the descent of all European, Indian, and .African luee 

 from the Asiatic Urus (B. nomadicus). He dealt \vi 

 the evidence to be derived from the maxillte, the ori ipi 

 and the temporal fossa", and stated his conclusions 

 follows : — (i) That the Celtic shorthorn {B. loitgiffuDs) 

 probably more intimately related to the zebu i..f Ind 

 {B. indicus) than to the European Urus (B. pfl'.itigi niu. 

 (2) That long premaxillge are usually correlated with i 

 occiput of the B. primigenius type, while short pi 

 maxillae are usually correlated with an occiput of t 

 B. acutifrons type. (3) That polled black Galloway call 

 and polled white " wild " Cadzow cattle are intimate 

 related to the Urus, that flat-polled .'\berdeen-Angus call 

 probably include amongst their ancestors an ancie 

 Oriental race now represented by, amongst oth'^r-;, 

 Syrian breed with rudimentary horns, and that roun 

 polled cattle may belong to a still more ancient Orient 

 race descended from B. acutifrons of the Punjab .Siwalil< 

 — G. P. Farran : Copepoda of the family Coryc.ieid 

 collected by Sir John Murray and Dr. C. W. Andrews 

 Christmas Island. The collection, though small in bul 

 was exceedingly rich in species, and the genus Corycae 

 was especially well represented. A new genus was pr 

 posed, and several new species were described and figure 

 — H. R. HogrST : Some New Zealand spiders. The pap 

 was based on a small collection sent by Prof. Charl 

 Chilton, of Christchurch, New Zealand. Twelve speci 

 and eleven genera were represented in the collection, ai 

 a new local variety of Tetragnatha frrox and four ne 

 .species were described. — Oldfield Thomas : Mamm£ 

 collected in the provinces of Kan-su and Sze-chwa 



