HARD WJ CKE S S CJENCE - G O SSIP. 



1 1 1 



cut off from the tree, although some small portions 

 may decay. If the eggs are sent as soon as they have 

 been laid, they will stand a voyage of fifteen or 

 sixteen days. If the larvae hatch during the voyage 

 they will feed at once, and many will survive and 

 grow during the three or four days they may remain 

 in the box. The leaves should be suspended, to 

 prevent the droppings of the larvoe remaining on 

 them, otherwise rot or fungus will ensue." 



To obtain a regular and continuous supply of leaf- 

 food, several small tin cases should be filled with 

 perfectly fresh sound and dry leaves, and then the 

 cases should be closed so as to be air-tight. These 

 cases should then be packed and forwarded in a 

 larger case, by this means permitting of a daily 

 supply being opened — one case at a time as required — - 

 and keeping the rest of the supply fresh until 

 needed. 



Lengths of stems or branches of trees can be kept 

 for some time in a fresh and healthy condition by the 

 cut ends being protected from the air by a coaling of 

 tar or sealing-wax. 



The establishment of a nursery of young tropical 

 plants under glass would be of great value, and 

 experience alone would prove the usefulness of allied 

 species. The hitherto assumed impossibility in 

 obtaining the requisite food to supply the wants of 

 tropical insects, we trust henceforth vanishes, and 

 becomes transferred from the region of " cannot be 

 done " to the more satisfactory position of accom- 

 plished facts. 



It should be especially noted that the names 

 given in the following pages are selected merely to 

 indicate the direction the management of an Insec- 

 torium should aim at. The difficulties in collecting 

 rare specimens, would, no doubt, be great in the 

 early stage of an exhibition of tropical insects, but, 

 when once accomplished, the reward would be still 

 greater, and Science would owe a debt impossible to 

 pay to those willing to bear the heat and burden of 

 the day, in accessibly placing for investigation and 

 study so valuable a treasure at her feet. 



"With the object once made known, numerous 

 friendly hands in our Colonies would eagerly offer 

 assistance, and, supplied with the proper cases for the 

 conveyance of their contributions, the furthest part of 

 the earth would be ransacked to yield its entomo- 

 logical wonders. 



(To be continued.') 



The April number of " The Journal of Microscopy 

 and Natural Science " contains the following original 

 papers, besides notes, etc. : " Cristatella tmecedo," 

 by R. H. Moore : "The Evolution of the Eye," by 

 Mrs. Bodington ; " External Anatomy of the Dor 

 Beetle," by Robert Gills: "The Homologies of 

 Certain Parts of Insects," by A. Hammond, etc. 



GOSSIP ON CURRENT TOPICS. 



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



The Cost of Electric Lighting. — The wild 

 anticipations concerning the electric light which were 

 fostered by company-mongers and prevailed so 

 ruinously among sanguine investors have been 

 effectually refuted ; but even now it is very difficult 

 to obtain accurate particulars concerning the cost of 

 its legitimate applications. Amongst these may be 

 particularly specified the application of electric 

 lighting in passenger steamships. Last year I 

 made a short trip in one of the New Zealand ships 

 of Messrs. Shaw, Saville, & Albion. Among all the 

 improvements carried out in these fine vessels none 

 are more striking than the substitution of the electric 

 lamps for the old swinging oil lamps. As colza oil is 

 a very costly illuminant, compared with gas or mineral 

 oils, it is quite possible that in such application an 

 economy may be effected, but in this case, where so 

 much steam generating fuel is used for other purposes, 

 it is not easy to separate the exact quantity consumed 

 in driving th'e dynamos. The practicability of 

 domestic lighting by electricity mainly depends on 

 the possibility of constructing a primary voltaic 

 battery with constant and economical action that 

 shall require no amalgamation of zinc plates, no 

 corrosive liquid elements, and very little skilled 

 attention. Such a battery may or may not be supple- 

 mented with a storage battery. M. Hospitalier has 

 been experimenting with about the nearest approxima- 

 tion to these desiderata that is at present available, 

 viz. a bichromate battery fitted with siphons to 

 secure a continuous automatic change of liquid with 

 secondary batteries connected. He finds that with 

 the utmost economy of working, and purchasing 

 materials at wholesale prices, the cost of a ten-candle 

 lamp is twopence per hour. An ordinary gas burner 

 consuming five to six cubic feet per hour gives a light 

 about equal to this. At three shillings per thousand 

 cubic feet, the cost of such a burner is less than one 

 farthing per hour. With a co-operative dynamo 

 supplying several houses, the cost would be less than 

 the above. 



An Electric Lighting Difficulty. — A curious 

 result of electric lighting has been recently displayed. 

 It is well known that the electric light has a powerfully 

 fascinating influence on night moths and other insects, 

 so much so that collectors have availed themselves of 

 it. Spiders are doing the same, to such an extent, 

 that the Treasury and other public buildings in 

 Washington have become seriously disfigured by 

 cobwebs since their white fronts have been illuminated 

 by the electric light. The more delicate architectural 

 ornamentation has been concealed, and when the 

 webs are blown down by the wind they hang in 

 slovenly and dirty rags that are by no means- 

 acceptable to aesthetic taste* 



