March 20, 1890] 



NATURE 



477 



Captain Watson, of the ship Charles Bal, at a spot about a 

 dozen miles off the island, records the phenomena of chains of 

 fire appearing to ascend between the volcano and the sky, while 

 on the south side there seemed to be a " continual roll of balls 

 of white fire." These appearances were doubtless caused by 

 the discharge of white-hot fragments of lava rolling down the 

 sides of the mountain. From midnight till 4 a.m. explosions 

 continually took place, the sky one second being intense 

 blackness, the next a blaze of fire. 



All the eye-witnesses agree as to the splendour of the electrical 

 phenomena. Captain Woolridge, viewing the eruption from a 

 distance of 40 miles, speaks of the great vapour cloud resembling 

 an immense wall, with outbursts of fork lightning, like large 

 luminous serpents, rushing through the air. After sunset, this 

 dark wall assumed the appearance of a blood-red curtain, with 

 the edges of all the shades of yellow — the whole of a murky 

 tinge, and attended with fierce flashes of lightning. It was 

 reported from the Lotidon that lightning struck the mast-head 

 conductor five or six times, and that the mud-rain which covered 

 the masts, rigging, and decks was phosphorescent. The rigging 

 presented the appearance of St. Elmo's fire, which the native 

 sailors were busily engaged putting out with their hands, 

 alleging that, if any portion found its way below, a hole would 

 burst in the ship ; not that they feared the ship taking fire, 

 but they thought the light was the work of evil spirits, and 

 that if it penetrated the hold of the vessel, the evil spirits would 

 triumph in their design to scuttle the ship. 



By these grand explosive outbursts the old crater of 

 Krakatab was completelyeviscerated, and a cavity formed more 

 than 1000 feet in depth ; while the solid materials thrown out 

 frorn^ the crater were spread over the flanks of the volcano, 

 forming considerable alterations in their forms. 



The sea disturbance which accompanied the eruption of 

 Krakatab was carefully investigated by Captain Wharton, 

 Hydrographer to the Admiralty :— "The rush of the great sea 

 wave over the land, caused by the violent abrasion in the crater, 

 aided by the action on the water of enormous masses of fallen 

 material, caused great destruction of life and poverty in the 

 Straits of Sunda. By the inrush of these waves on land, all 

 vessels near the shore were stranded, the towns and villages near 

 the coast devastated, two of the lighthouses were swept away, 

 and the lives of 36,380 of the inhabitants sacrificed. It was 

 estimated that the wave was about 50 feet in height when it 

 broke on the shore." 



On the morning of the 27th, between 10 and 11 a.m., three 

 vessels at the eastern entrance of the Straits encountered the fall 

 of mingled dust and water, which soon darkened the air, and 

 covered their decks and sails with a thick coating of mud. 

 Some of the pieces of pumice falling on the Sir R. Sale were 

 said to have been of the size of a pumpkin. All day on the 27th, 

 the three vessels were beating about in darkness, pumice-dust 

 falling upon them in such quantities as to employ the crew for 

 hours in shovelling it from the decks and in beating it from the 

 sails and rigging. At Batavia, 100 miles from Krakatab, the 

 sky was clear at 7 a.m., but at 11 a.m. there fell a regular dust- 

 rain ; at ir.20 complete darkness pervaded the city. The rain 

 of dust continued till i, and afterwards less heavily till 3 p.m. 



The speed and distance attained by the pumice ejected from 

 the volcano may be conceived from the fact staled in Mr. 

 Douglas Archibald's contribution to the Report, that dust fell on 

 September 8, more than 3700 English miles from the seat of 

 the eruption. 



The great mass of the pumice thrown out during the eruption 

 presented a dirty greyish- white tint, being very irregular in size. 

 It was undoubtedly due to the collision of fragments of pumice 

 as they were violently ejected from the crater ; the noise pro- 

 duced was even more striking than the sound of the explosion. 



The dust ejected from Krakata~o did not all fall back at the 

 same time upon the sea and earth ; as the lightest portions 

 formed into a haze, which was propagated mostly westward. 

 Mr. Archibald states in the Report that most observers agree 

 upon considering this haze as the proximate cause of the twilight 

 glows, coloured suns, and large corona, which were seen for a 

 considerable time after the eruption. The haze was densest in 

 the Indian Ocean and along the equatorial belt, and was often 

 thick enough to hide the sun entirely when within a few degrees 

 from the horizon. 



And now, ladies and gentlemen, I must bring this address to a 

 conclusion, and thank you for having followed me over a long, 

 dusty track. I hope I have succeeded in showing that infinitely 



small objects, no larger than particles of dust, act important 

 parts in the physical phenomena of Nature, just as small and 

 apparently unimportant events occasionally lead to others of the 

 greatest magnitude. 



SOCIETIES AND ACADEMIES. 

 London. 

 Royal Society, March 6.— "The Cranial Nerves of the 

 Torpedo" (Preliminary Note). By J. C. Ewart, M.D. Com- 

 municated by Prof. M. Foster, Sec. R.S. 



The cranial nerves of the torpedo agree in their general 

 arrangement with those of the skate.' The ophthalmicus ))ro- 

 fundus occupies the usual position, but its ganglion lies in close 

 contact with the Gasserian, and not on a level with the ciliary, 

 ganglion. The trigeminus has the usual distribution, for, not- 

 withstanding the statements in the most recent text-books,'-' the 

 trigeminus sends no branch to the electric organ. The facial 

 complex includes the superficial ophthalmic, the buccal, and the 

 hyomandibular nerves, all of which have the same distribution 

 as the corresponding nerves in the skate ; but the hyomandibular 

 includes or is accompanied by a large bundle of nerve fibres 

 which supply the anterior and inner portion of the electric 

 organ. This large nerve cord (the first electric nerve) has 

 hitherto almost invariably •' been described as a branch of the 

 trigeminus. When traced backwards, it is found to spring from' 

 the anterior portion of the electric lobe. 



The glossopharyngeus, a slender nerve in the skate, is repre- 

 sented in the torpedo by a thick cord which escapes by a large 

 foramen in the outer wall of the auditory capsule. This large 

 nerve consists of two portions, one of which is small and com- 

 pletely covered by the large superficial division. The small deep 

 division, which in its course and distribution closely resembles 

 the glossopharyngeal in the skate, presents on leaving the 

 auditory capsule a distinct ganglionic swelling, beyond which it 

 breaks up into the branchial and other branches. The large 

 superficial division emanates from the electric lobe behind the 

 origin of the first electric nerve, and at once runs outwards to 

 reach and supply the majority of the columns of the anterior 

 half of the electric organ. 



The va.gus complex consists of the nervus lateralis, the nervus 

 intestinalis, and of five branchial nerves, of which the two 

 anterior are accompanied by the third and fourth electric nerves. 

 The nervus lateralis, lying superficial to all the other nerves, 

 arises on a level with the root of the glossopharyngeus, and then 

 curves backwards dorsal to the posterior electric nerve to reach 

 the canal of the lateral line. Shortly after leaving the cranium it 

 presents a distinct ganglionic swelling, which is crowded with 

 large cells. The four branchial nerves for the four vagus 

 branchiae, the slender filament which represents a sixth branchial 

 nerve, and the intestinal nerve lie at first in contact with each 

 other under cover of the third and fourth electric nerves. When, 

 the branchial and intestinal nerves are carefully examined, they 

 are found to present four, sometimes five, ganglionic enlarge- 

 ments, and in addition ganglionic cells can sometimes be detected 

 at the proximal end of the slender sixth branchial nerve. The 

 third and fourth electric nerves lie over and are especially related 

 to the second and third branchial nerves. These large electric 

 nerves spring from the posterior half of the electric lobe, and find 

 their way outwards partly behind and partly under the auditory 

 capsule, to terminate in the posterior half of the electric organ. 

 It thus appears that all the electric nerves spring from the 

 electric lobe, that the first accompanies the hyomandibular 

 division of the facial complex, the second the glossopharyngeus, 

 and the third and fourth the first two branchial nerves of the 

 vagus complex. It remains to be seen whether the electric 

 nerves have been derived from motor branches of the nerves 

 with which they are respectively associated by an enormous 

 increase in the number of their fibres, as the muscular fibres- 

 were gradually transformed into electric plates. 



Physical Society, Feb. 21.— Prof. G. Carey Foster, F. R.S.,. 

 Past- President, in the chair. — The following communications 

 were read :— On a carbon deposit in a Blake telephone trans- 



' Ewart, " On the Crani.il Nerves of Elasmobranch Fishes," Roy. Soc. 

 Proc, vol. 45, 1889. 



^ Eg-, McKendrick, " Text-book of Physiology," 1888, and Wiedersheim, 

 " Grundriss der vergleichenden Anatomic," 1888. 



3 Fritsch is the only author I am acquainted with who does not describe 

 the first electric nerve .is a branch of the trigeminus, " Untersuchungen 

 ueber den feineren Ijau des Fischgehirns," Berlin, 1878. 



