Nov. 7, 1878] 



NATURE 



21 



.-iitions is very clear and precise. He assigns, in his will, 



jI. a year as the salaiy of a reader in anatomy ; 50/. for ex- 1 



ses of two bodies and dissection ; 30/. to a reader in mathe- 



.....tics and physics, and the remainder to be given in annual i 



J -•-izes of 10/. to scholars from Westminster School. The trust 



;; now worth 3,400/. annually. It is spoken of in the return I 



le by Christ Church to the Commissioners of 1874 as " Dr. I 



j's Benefaction for Senior Students in Natural Science." 1 



: uii is not quite accurate : firstly, because Dr. Lee designed the j 



n.ajor portion of his benefaction for students in anatomy as 1 



^aring on medicine, and not for natural science generally ; and, i 



: Dndly, because Christ Church uses nearly half of Dr. Lee's , 



.it-money to pay classical scholars from Westminster School ; i 



ilst the remainder is used to support a most efficient chemical I 



jratory, and to pay, in part, the salaries of the accomplished { 



iinist, zoologist, and physicist, who are styled " Lee's i 



aders." Nopartof Dr. Lee's bequest is now assigned to medical 1 



. lies, though it should be stated that the present application j 



Dr. Lee's fund has obtained Parliamentary sanction. 



OX THE THERMAL PHENOMENA PRODUCED 

 BY THE PASSAGE OF ELECTRICITY 

 THROUGH RAREFIED GASES ^ 



A PORTION of the experiments described in this paper were 

 •^~*- made before the publication of Wiedemann's experiments 

 • . the same subject. The authors state that if they had known 

 the work of the German physicist they would probably not 

 . e undertaken the investigation, but they have continued the 

 ; eriments and think them worthy of description as the methods 

 .ployed differ from those of Wiedemann. 



The apparatus used consisted of ordinary Geissler tubes, the 



electrodes being in wide tubes connected by a narrow one. A 



" -:;e Ruhmkorff's coil with a secondary wire 100,000 metres in 



gth was set in action by tw'o large Bunsen cells, and the 



.ent was made and broken by a Foucault's interrupter. In 



er to measm-e the induced current a reflecting galvanometer 



s employed, being placed at such a distance from the coil 



i the effect of the electro-magnet on the needle was very 



..ill; this slight deviation was, however, applied as a cor- 



tion in all the readings. It was first proved that the current 



uced on completing the primary circuit was incapable of 



-.ling through the Geissler tube, for the galvanometer needle 



^1 equally deflected whether placed in the secondary circuit 



not, indicating that the movement of the needle was due 



^;Iy to the direct action of the magnet of the coil; on the 



..trary, when the primary circuit was broken, a considerable 



lection of the needle occurred when the galvanometer was in 



- secondary circuit, and a slight one, but in the opposite 



ection, when the needle was influenced by the magnetism of 



. coil alone. 



Tubes containing chlorine, carbonic anhydride, and hydrogen, 



;re employed in the experiments, the electrodes being soldered 



the ^Nires from the coil by means of Wood's fusible alloy. 



e narrow part of the tube was placed in a copper cylinder 



-■.aining water, or preferably mercurj', in which a delicate 



.imometer was immersed, the deflection of the galvanometer 



5 read every thirty seconds, and the thermometer every 



iiiute. When the current indicated by the galvanometer was 



greatest the increase of temperature was most rapid, but the 



important fact shown by these experiments is that in every case 



the rise of temperature divided by the deflection is a constant. 



Unfortunately the different constants are not comparable, as the 



experiments were not made with the same tube containing the 



different gases at known pressures, but with different tubes of 



nearly the same sizes ; but the pressures of the gases are not 



given. 



Some experiments were undertaken to determine the heating 

 effects in the neighbourhood of the electrodes. For this purpose 

 the upper end of a Geissler tube containing chlorine was placed 

 in the calorimeter, the latter surrounding the part of the tube 

 containing the platinum wire. When the electrode was negative 

 about eight times more heat was developed than when it was 

 positive. As the quantity of heat produced when the electrode 

 -was positive was verj' small the relation between the deflection 

 of the galvanometer and the rise of temperature was not so 

 regular in the different experiments as in the other case ; and 

 when the electrode was negative it was obser\-ed that the quan- 



' By Dr. Naccari and M. Bellati (vol. iv. ser. v., degU Aiii del R. Insti- 

 tulo veneto de Science, Lettere ed Arti). 



tity of heat increased a little more rapidly than the deflection. 

 More accurate results were obtained by immersing the lower 

 end of the tube in the calorimeter ; under these circumstances 

 the quantity of heat collected when the electrode was negative 

 was 22'8 times as great as in the experiments in which it was 

 positive, and while the deflection of the galvanometer varied 

 from 100 to 640, the rise of temperature divided by the deflec- 

 tions increased from ico to 120 only. 



It being suspected that the different effects at the two elec- 

 trodes might be due to a cause similar to the Peltier effect in 

 solid conductors, an attempt was made to discover if the posi- 

 tive electrode is cooled during the passage of the electricitj*. 

 There appeared to be a very slight diminution of temperature at 

 the commencement of the experiment, but it was soon marked 

 by the conduction of heat from other parts of the tube. 



The calorimeter was next placed on the wide part of the 

 Geissler tube, but not surroimding the electrode, which wak 

 i6'5 mm. from the calorimeter. In this case, also, a larger 

 quantity of heat was developed near the negative electro I e 

 than near the positive, but the ratio was only 4*9. When a 

 portion of the narrow part of the tube was placed in the calori - 

 meter, that near the negative electrode was slightly more heated 

 than the other portion. When a tube containing hydrogen was 

 used similar results were obtained, but the difference between 

 the quantities of heat at the two ends was very much less than 

 in the case of chlorine. 



The next series of experiments was made to determine the 

 effect of different diameters of tube. For this purpose a U-tube 

 containing air of the pressure of two mm. was used, one 

 limb of the tube having a sectional area of 36'3 square mm., 

 the other 1 2 '6 square mm., both limbs being surroimded by 

 calorimeters. The quantity of heat developed in the narrow 

 tube was only very slightly greater than in the other, the ratio 

 being about I'l. By using another tube with the areas of Ii6'9 

 square mm. and 4*5 a similar result was found, but in this case 

 the ratio was not greater than I "2. 



NOTES FROM NEW ZEALAND 



'T'HE following notes have been sent tis from New Zealand 

 -'■ by Mr. T. H. Potts, of Ohinitahi :— 



Maari Food Feast. — At the great meeting of Kingite natives 

 convened by Tawhaio to meet Sir George Grey and the Hon. 

 Native Minister, amongst other very interesting incidents was 

 the food feast which was held at Hikurangi on May 8. 



A procession formed of several hundreds of women, each 

 carrying a neatly woven basket filled with food, proceeded 

 through the village till it arrived opposite to Sir George Grey's 

 tent ; at a given signal the baskets were placed on the ground 

 and stacked into a huge heap. The presentation of each article 

 of food was accompanied with an appropriate chant or ngori, 

 with dancing and facial contortions of an extraordinary cha- 

 racter, many of the most ancient persons of different hapus 

 taking part in the celebration. 



Amongst the various articles of vegetable food in season was 

 offered : — 



Pohua. — The root of Convolvulus sepium, as flowery as a 

 potato with a slightly bitter taste. 



Sowthistle. — Sonchus oleraceus. The Hauhans, when com- 

 pelled to use cooked sowthistle, found to their surprise they did 

 not lose condition on this spare diet. 



Para. — The thick solid scale from the rootstock of the grand 

 fern Marattia fraxinea. This edible was pinkish or pale purple 

 w hen cut, solid, tough, almost tasteless, with a slightly bitter 

 flavour. 



Marnaht. — This esculent appeared in thick junks of about a 

 foot in length ; it is the mucilaginous pith of the great black 

 tree-fern Cyathea medullaris. It was presented ready dressed, 

 was soft, very sweet to the palate. 



Roi. — The rhizome or root of the bracken Pleris aquUina, 

 var. esculeftta. It was offered in the uncooked state, in which 

 it is usually kept ready for use. 



Taw/ia. — ^The prepared berries of a common forest tree 

 Nesodaphne tawha. 



Hakeke. — The Jew's-ear fungus Himeola auricula-ynda. It is 

 found in the forests of Pirongia; that which grows on the 

 Karaka is most esteemed. 



On Moa Remaim, &^c. — There has been so warm a controversy 

 as to the probable datej,of the extinction of the dinomis, tliat 



