338 



SCIENTIFIC NEWS. 



[April 13 



will be green on the Asiatic, and red on the African side 

 of the canal. The gas will be made at the Company'3 

 existing works at Port Said, and all the arrangements are 

 so far forward that it is expected the whole system will 

 b^ in working order next autumn. 



We believe that before coming to a decision on the 

 very important question as to what system would best 

 fulfil the requisite conditions, the Company very carefully 

 considered various means of lighting by oil and electricity 

 as well as by gas. Compressed gas carried the day so 

 far as the lighting of the canal itself is concerned, but all 

 vessels navigating at night are to carry electric lights. 

 The forepart of each vessel must be provided with an 

 electric projection lamp capable of throwing a light 1,200 

 meters ; there must also be a shaded electric light sus- 

 pended over the deck capable of illuminating a circular 

 field about 200 metres in diameter. No steamer will be 

 allowed to proceed at night time until the authorities at 

 Port Said or Port Tewfik are satisfied that her lighting 

 appliances fulfil the required conditions. In this waj' it 

 is hoped that the present carrying power of the canal 

 will be nearlj' doubled. This may be a somewhat san- 

 guine view to take, as, however perfect the lighting appli- 

 ances may be, they can hardly admit of traffic being 

 carried on as quickly and as surely as by day-light. At 

 least the new system will give great relief to the canal 

 traffic, and will be welcomed bj' shipowners. 



SCIENTIFIC TABLE TALK. 



By W. Mattieu Williams, F.R.A.S., F.C.S. 

 In the East-end of London are some large warehouses 

 in which are stored above 1,000 tons of flour. The 

 guardians and proprietors of this considerable stock were 

 alarmed last summer on discovering that a serious 

 quantity had become changed into something more like 

 dirty wool than respectable flour. One of the interested 

 merchants was Mr. Sydney Klein, an earnest entomolo- 

 gist, who at once discovered the nature of the metamor- 

 phosis. He found that it was effected by a prettj' and 

 detestable little butterfly, which bears the name of 

 Ephestia Kithinclla, and is too well known in the ports of 

 the Mediterranean where farinaceous matter is stored. 

 A supply of these was imported with some of the 

 flour, and the fond mothers of prospective offspring care- 

 fully provided for the babes they could not live to see 

 by piercing the sacks, and each laying her hundreds of 

 eggs therein, where food was provided in abundance. 

 The eggs hatched into caterpillars, the happy creatures 

 ate the rich food in which they were so luxuriously 

 buried, pursued their wonted industry of spinning and 

 weaving "until one entire warehouse was literally 

 smothered, thousands of the larvae on every sack, and 

 many hundred pounds-worth of damage done ; the flour 

 was so interwoven with larvae threads that it was 

 rendered unfit even for pig or cattle food." 



This occurred and continued in spite of systematic and 

 scientific attack made under the superintendence of Mr. 

 Klein. Fumigations with sulphur, hot liming of floors, 

 ceiling, and walls, though killing immense numbers failed 

 to overcome the enemy. The larvje which reached full 

 growth in about four weeks were seen in myriads 

 crawling along the floor and up the walls until they 

 reached the angle between walls and ceiling, where 

 they spun their silken cocoons, in which they reposed 

 until qualified for the parentage of new multitudes. 



Mr. Klein then transplanted a colony to his house in *, 



order to study their habits, placing them in insect-breed- 

 ing cages, and imder large glass shades, but the young 

 caterpillars squeezed through the meshes of the finest 

 wire gauze, grovelled under the shades, and presently- 

 appeared in all parts of the house spinning cocoons in 

 the upper corners of every room, after feeding on what- 

 ever farinaceous matter they could find. The remains 

 of the colony were given by Mr. Klein to his fowls, and 

 were devoured eagerly. This suggested another line of 

 attack. A large number of fowls were placed in the 

 warehouse. They consumed enormous quantities of the 

 larvae, but after about ten minutes' gorging became less 

 energetic, and in the meantime the insects continued to- 

 increase and spread to other granaries in the neigh- 

 bourhood, threatening the extinction of an important 

 local industry. In July Mr. Klein had all the flour of 

 one warehouse passed through fine sieves, and the larvae 

 and their refuse destroyed, but within a few weeks this 

 flour was again swarming with grubs. Other able 

 entomologists were consulted, but no effective remedy 

 was forthcoming, when, to quote the words of Mr. Klein, 

 " Science having failed to find a remedy it remained for 

 Nature to step in with those wonderful antidotes which 

 she always has in store for counteracting any over-pro- 

 duction of the flora and fauna under her charge." 



In August he observed some dark markings on the 

 backs of the larvae, and in September an extraordinary 

 change had occurred. The tops of the flour sacks were 

 perfectly black, as though covered with soot. Close 

 examination proved this to be due to enormous numbers 

 of a small black fly, one of the Ichneumonida, specially 

 constructed for depositing its eggs in the bodies of the 

 young flour-eating caterpillars, wherein the eggs 

 hatched to avenging maggots that fed upon the internal 

 arrangenients of the caterpillars, and finally leaving but 

 a dead skin. The marks seen by Mr. Klein were due to 

 these creatures in the maggot stage. 



Mr. Klein concludes the paper that he read on the 

 subject at the Middlesex Natural History and Science 

 Society by admiring the proceedings of Nature who had 

 thus "come to the rescue and provided a remedy herself." 

 This admiration was evidently from a Corn Exchange 

 point of view, not from that of the Ephestia Kiihinella. 



The Ichneumon appears to be a species new to science. 

 The Ephestia were finally traced by Mr. Klein to some 

 meal shipped from Fiume, on the Adriatic, over two 

 years ago. As the moths did not appear until last 

 summer, he attributes their extraordinary increase 

 and ravages to the hot and dry summer. 



Specimens of the imagos, pupae, and larvae of the 

 Ephestia Kiihinella, together with the extirpating. 

 Ichneumonida, are now displayed at the British Museum, 

 of Natural History, South Kensington. 



Dr. Goldschneider has recently investigated the very 

 curious fact that when carbonic acid gas of a given tem- 

 perature is brought in contact with the skin, it appears 

 much warmer than air of the same temperatuie. I well 

 remember standing in the Grotta del Cane, and distinctly 

 feeling the surface level of the pool of carbonic acid by 

 the sensation of heat reaching a little above the knees. 

 I then supposed the gas to be really hot, rising as it does 

 from an active volcanic region. Doubtless others have 

 observed the same and have arrived at similar conclu- 

 sions, but it now appears that with the gas of the same 

 temperature as the air above it, the warm-bath sensation 

 would be felt up to the level of the gas, and that this is 



