11^8 ANNUAL OP SCIENTIFIC DISCOVERY. 



tion that which they saw a moment previously by direct vision. 

 The actor, standinG: at a sufficient distance behind the fj^lass, is 

 completely hidden tVom view, and he is again ri'ndered visible by 

 turning down the light on the false scene, and allowing the stage 

 lights to }5redominate. When "Eidos iEidcs" was being per- 

 formed at Her Majesty's Theati-e, it was, however, possible, with a 

 good ojiera-glass, to distinguish the outline of the figure behind 

 the plate. The effects produced may, of course, be modified. An 

 actor may be made to appear walking or flying in the air, or 

 dancing on a tight-rope, by eclipsing or obscming a raised platform 

 on which he may be placed. — Reader. 



WHY BEES WORK IN THE DARK. 



A life-time might l)e spent in investigating the mysteries hidden 

 in a bee-hive, and still half of the secrets would be undiscovei-ed. 

 The formation of the cell has long been a celebrated problem for 

 the mathematician, whilst the changes which the honey undergoes 

 offer at least an equal interest to the chemist. Every one knows 

 what honey, fresh from the comb, is like. It is a clear, yellow 

 syrup, without a trace of solid sugar in it. Upon straining, how- 

 ever, it graduall}' assumes a crystalline appearance ; it candies, as 

 the saying is, and ultimately becomes a solid lump of sugar. It 

 has not been suspected that this change Avas due to a photographic 

 action ; that the same agent which alters the molecular arrange- 

 ment of the iodide of silver on the excited collodion jjlate, and de- 

 termines the formation of camphor and iodine crystals in a bottle, 

 causes the syrup}' honey to assume a crystalline form. This, how- 

 ever, is the case. M. Scheibler has enclosed honey in stoppered 

 flasks, some of which he has kept in perfect darkness, whilst oth- 

 ers have been exposed to the light. The invariable results have 

 been that the sunned portion rapidly crystallizes, whilst that kept 

 in the dark has remained perfectly liquid. We now see why bees 

 are so careful to Avork in perfect darkness, and why they are so 

 careful to obscure the glass windows which are sometimes placed 

 in their hives. The existence of their young depends on the liquid- 

 ity of the saccharine food presented to them, and if light wei'e al- 

 lowed access to this, the syrup would gradually acquire a more 

 or less solid consistency ; it would seal up the cells, and, in all 

 probabilit}', prove fatal to the inmates of the hive. — Chronicle of 

 Optics, in the Quarterly Journal of Science. 



NEW ARTIFICIAL LIGHT. 



Mr. James Wilkinson, of Chelsea, is endeavoring to rival the 

 magnesium light for photographic purposes, by means of a mix- 

 ture of phosphoi'us and nitrate of potash. He recently burnt a 

 quarter of a pound of this mixture in his garden, at night, with a 

 view to obtain a photograph of a wind engine which was being 

 erected in an adjoining garden, and he states that " the length of 

 time from when it was first lit until it was finally burnt out, was 

 nearly six minutes. The utmost cost was a fraction over four- 



