April 22, 1880] 



NATURE 



589 



tion in each particular case. As employed by Malays, who are 

 followed both by Dutch and English travellers, the word has 

 scarcely better standing-ground in a scientific terminology than 

 has "Alfuro." 



The following fact with regard to the Sea Dyaks may be of 

 interest. When Europeans first entered Sarawak the Kayans, 

 properly so called, were dominant in the great Rejang Kivei, 

 and the Sea-Dyaks were strictly confined to the Batang Lupar, 

 Saribas, and Kalakah rivers. Now the Sea-Dyak population of 

 the Rejang is some 30,000, and the Rejang Dyaks are rapidly 

 occupying the Oyah, Mukab, and Tatau rivers further up coast. 

 On the original Sea-Dyak rivers the people always use the 

 expression "we Dyaks" when they mention their own race; 

 but on the Rejang the expression " we Iban " will invariably be 

 heard — the explanation being that the Kayans habitually desig- 

 nate Sea-Dyaks as " Ivan " among themselves, whence the 

 Dyaks have applied the name ; but having no v-sound in their 

 language, they say " Iban." The Kayan proper is rich in 

 v-sounds. I have been informed, though I cannot vouch for the 

 accuracy of the statement, that "Ivan" in Kayan is a term 

 carrying with it a sense of opprobrium. However this may be, it 

 is remarkable that so large a section of the Sea-Dyaks, who are 

 so thoroughly dominant in Rejang, and are in constant daily 

 communication with their original seat in the rivers to the west- 

 ward, should in the course of some thirty years have come to 

 habitually speak of themselves by the name given them by their 

 foes. And it is the more surprising because the Sea-Dyaks 

 generally give new names of their own to the geographical 

 features of the district into which they immigrate. 



Papar, North Borneo A. Hart Everett 



Seeing by Electricity 



We hear that a sealed account of an invention for seeing by 

 telegraphy has been deposited by the inventor of the telephone. 

 Whilst we are still quite in ignorance of the nature of this inven- 

 tion, it may be well to intimate that complete means for seeing 

 by telegraphy have been known for some time by scientific men. 

 The following plan has often been discussed by us with our 

 friends, and, no doubt, has suggested itself to others acquainted 

 with the physical discoveries of the last four years. It has not been 

 carried out because of its elaborate nature, and on account of its 

 expensive character, nor should we recommend its being carried 

 out in this form. But if the new American invention, to which 

 reference has been made, should turn out to be some plan of this 

 kind, then this letter may do good in preventing monopoly in an 

 invention which really is the joint property of Willoughby Smith, 

 Sabine, and other scientific men, rather than of a particular man 

 who has had sufficient money and leisure to carry out the idea. 

 The plan, which was suggested to us some three years ago more 

 immediately by a picture in Punch, and governed by Willoughby 

 Smith's experiments, was this :— Our transmitter at A consisted 

 of a large surface made up of very small separate squares of 

 selenium. One end of each piece was connected by an 

 insulated wire with the distant place, B, and the other end 

 of each piece connected with the ground, in accordance with 

 the plan commonly employed with telegraph instruments. 

 The object whose image was to be sent by telegraph was 

 illuminated very strongly, and, by means of a lens, a very 

 large image thrown on the surface of the transmitter. Now it 

 fa well known that if each little piece of selenium forms part of a 

 circuit in which there is a constant electromotive force, say of a 

 Voltaic battery, the current passing through each piece will 

 depend on its illumination. Hence the strength of electric 

 current in each telegraph line would depend on the illumination 

 of its extremity. Our receiver at the distant place, B, was, in our 

 original plan, a collection of magnetic needles, the position of each 

 of which (as in the ordinary needle telegraph) was controlled by 

 the electric current passing through the particular telegraph wire 

 with which it was connected. Each magnet, bv its movement, 

 closed or opened an aperture through which liglit passed to illu- 

 minate the back of a small square of frosted glass. There were, 

 of course, as many of these illuminated squares at B as of sele- 

 nium squares at A, and it is quite evident that since the illumina- 

 tion of each square depends on the strength of the current in its 

 circuit, and this current depends on the illumination of the 

 selenium at the other end of the wire, the image of a distant 

 object would in this way be transmitted as a mosaic by electricity. 



A more promising arrangement, suggested by Prof. Kerr's 

 experiments, consisted in having each little square at B made of 

 silvered soft iron, and forming the end of the core round which 



the corresponding current passed. The surface formed by these 

 squares at B was to be illuminated by a great beam of light 

 polarised by reflection from glass, and received again by an 

 analyser. It is evident that, since the intensity of the analysed 

 light depends on the rotation of the plane of polarisation by 

 each little square of iron, and since this depends on the strength 

 of the current, and that again on the illumination of the selenium, 

 we have another method of receiving at B the illumination of the 

 little square at A. It is probable that Prof. Graham Bell's 

 description may relate to some plan of a much simpler kind than 

 either of ours ; but in any case it is well to show that the dis- 

 covery of the light effect on selenium carries with it the principle 

 of a plan for seeing by electricity. John Perry 



Scientific Club, April 21 W. E. Ayrton 



Musical Sounds within the Ear 

 I should like to know how far the musical sounds, which we 

 sometimes hear within our ears, are of different pitch in different 

 persons. From repeated observations I find that my left ear 

 gives G, and the right one B. A friend of mine, who is a good 

 performer on the violin, finds F and A respectively. 



It is perhaps not without interest that in some parts of Germany 

 (at least in Silesia) people believe these sounds to be indicative 

 of one's being talked about, and that the sound ceases as soon as 

 one thinks of the person who is supposed to do so. 



Caracas March iS a. Ernst 



Ice Filaments 

 "The comb-shaped masses of ice of fibrous structure" men- 

 tioned by your correspondent, in explanation of the inquiry made 

 by the Duke of Argyll, are observed every winter in the southern 

 portion of the United States, especially on the sloping sides of a 

 path or country road where the surface-earth has been removed, 

 and the natural clay subsoil is not rendered compact by being 

 trodden. The conditions requisite for its abundant production 

 are a sudden reduction of temperature below the freezing-point 

 when the clay soil is thoroughly saturated with water, "when 

 this occurs at sunset, the next morning, if the night continues 

 favourable, will disclose a vast collection of fibrous filaments, 

 from two to six inches in height, rising from the soil in close 

 juxtaposition, generally holding aloft in their caps portions of 

 the soil, the longest crystals appearing when the soil is free from 

 surface-loam. 



I have frequently given to my class this explanation of the 

 phenomena. 



The capillary tubes of the soil are all filled up to the surface 

 with water. The sudden reduction of temperature freezes the 

 water at the surface, but does not chill it 

 within the soil below 32 F. The con- 

 sequence is that this expansion, caused 

 by congelation at the upper extremity of 

 g^== the capillary tube, compresses the walls of 

 the tube externally, and causes the mouth 

 of the tube at the surface to assume a 

 conical shape, as in diagram. The conge- 

 lation of all the water within the conical 

 cavity causes pressure normal to the sur- 

 face of the cone at a and l>, and hence 

 produces a vertical resultant, r, that raises 

 the cone of ice. Capillary action imme- 

 diately fills the little cavity with water, 

 which in turn is frozen and elevated by the 

 expansion force of its congelation. The 

 filament thus grows in this simple way from its base. The soil 

 in which thee fibrous crys'als or filaments form is never frozen; 

 thus proving the correctness of the explanation. 



They are formed very rapidly. I have on more than one 

 occasion, when a sudden chill at sunset would start them growing, 

 listened to the crackling of the little ice-crystals as they would 

 break loose from each other, being pushed up by this expansive 

 force. 



I infer the filaments of ice formed on rotten wood are due to 

 a similar cause, and that they will not be formed unless the 

 reduction of temperature is quite sudden. That is, if the reduc- 

 tion of temperature is so gradual that the water somewhat below 

 the surface in the cylindrical portion of the capillary tube is 

 frozen, the crystals will not be elevated, but the ground will be 

 frozen. Wm, LeRoy Broun 



Vanderbill University, U.S. 



