30 



HARDWICKE'S SCIENCE-GOSSIP. 



results of earnest devotion to Science. The gloomy 

 visions of a wicked, ill-fashioned world, and dread of 

 a worse to come, which darken the later moments of 

 so many of those who have groped through life in the 

 midst of artificial darkness due to the blindness of 

 ignorance, is impossible to men who have earnestly 

 explored the wondrous harmonies of Nature, and have 

 done so not merely for trading purposes, but with 

 genuine scientific enthusiasm. Neither the past nor 

 the future can appear ill-shapen and miserable to them. 



The influence of coloured light on plants, concern- 

 ing which such contradictory conclusions have been 

 formed, has been further studied by Hellriegel. In 

 his later researches he arranged the plants so that 

 they should have the benefit of free air during fine 

 weather, and be removed to shelter in bad weather, 

 instead of keeping them continuously in a glass 

 house. Better general results were thus obtained. 

 Barley plants were grown under blue cobalt glass 

 and yellow carbon glass. Less ash and more 

 organic matter were produced under the blue than 

 under the yellow. Those under the blue glass grew 

 well, while those under the yellow seemed to be 

 retarded, and when shaded were long in the inter- 

 nodes, and the leaves were thin and delicate. The 

 general conclusions derived from these and other 

 experiments are, that leaves are not very sensitive 

 to moderate changes in the composition of the light 

 to which they are exposed, and consequently that the 

 modifications of light produced by the ordinary glass of 

 greenhouses can have but little effect, so little that 

 there is no practical necessity for specially selecting 

 the glass used for this purpose. 



The persistence of an old fallacy has been 

 curiously shown by a paragraph which has lately 

 "gone the round" of the daily papers. After 

 describing the bursting of water mains in Buchanan 

 Street and Paisley Road, Glasgow, and the stoppage 

 of the music in the churches having hydraulic organs, 

 we are told that " sudden thaw after the severe 

 frost caused the bursts." 



Another popular fallacy, not quite so elementary, 

 is continually breaking out among newspaper corre- 

 spondents. The following, written from Vevey, 

 appeared in "Nature," December nth. "On the 

 night of November 28th, at about six in the evening, 

 I went to the window to look at the moon, and saw, 

 as it were, a second moon, behind the other. The 

 effect was so like what one sometimes experiences 

 from suddenly going out of a light room, or other 

 causes (my own italics) that, at the time, I fancied it 

 was only a defect in my sight. On going into my 

 son's room an hour afterwards, he said, * If something 

 has not gone wrong with my eyes there are two 

 moons to-night.' On this I went out again, but only 

 saw one moon "as usual. Later in the evening, a 

 young girl who had been meeting a friend at the 

 Montreux train, said her friend had said the moon 

 looked queer all the while she was in the train. 



The night previous a pretty severe shock of earth 

 quake occurred in Geneva and Lausanne, and 

 a few hours after we had observed the moon on 

 the 28th a very violent gale and snowstorm took 

 place." It should be noted that this account states 

 that each of the observers saw the double moon 

 through windows, and that the writer only saw one 

 moon "on going out." Herein lies the explana- 

 tion without invoking any of the "other causes" to 

 which temporary double vision is usually attributed. 

 The moon, or any other luminous object viewed 

 obliquely through a pane of glass, is always visually 

 doubled. The light passing obliquely through the 

 side of the glass next to the luminous object is 

 reflected when it reaches the inner surface next to 

 the observer, and then is re -reflected by the opposite 

 inner surface, and thrown towards him. This second 

 reflected image appears near to the directly trans- 

 mitted image, but is not coincident with it, the 

 distance between varying with the thickness of the 

 glass. When the object is large, it only appears 

 to have blurred outlines, when small the true double 

 character of the image is evident. Double stars may 

 thus be discovered without any telescopic aid. 



After all the protection and subsidies and bounties 

 that have been bestowed on that very political 

 agricultural product, beet sugar, it is now in danger 

 of being outrivalled by Sorghum sugar. German and 

 French chemists are working out the scientific 

 elements of the problem. In Biedermann's Central- 

 blatt, V. Pfuel describes his experiments on its culti- 

 vation, finds that when the seed ripens there is 15 

 per cent, of sacchrose present ; before that time, only 

 from one to three per cent. After the autumn cutting 

 the plants throw up a good fodder for sheep. N. 

 Minangoin, in the same journal, says that Sorghum 

 may be cultivated in France at less cost than beet, 

 that its yield of molasses is less, but good brandy is 

 obtainable from it, and the residue makes good 

 fodder. Beet and Sorghum are evidently running a 

 close race, with the advantage of the start and 

 consequent experience and skill, on the side of the 

 beet. But this may not be maintained. 



Two elaborate, and from a purely chemical point 

 of view, able papers are contributed to Dingler's 

 Polytechnisches Journal by E. Valenta, onjhe action 

 of glacial acetic acid on different oils. One of the 

 results of these researches, which the author claims, 

 is the detection of the adulteration of mineral oils 

 with resin oils, the resin oils being soluble in acetic 

 acid, the mineral oils almost insoluble. The idea of 

 such adulteration is rather amusing now that these 

 mineral lubricating oils are so much cheaper than the 

 imaginary adulterant. I find by the price current in 

 last month's " Oil Trade Review," that the heavy 

 mineral lubricating oils go as low as £5 per ton, i.e. 

 about fivepence per gallon ; the light mineral oils 

 range from 6\d. to n\d. per gallon, while light resin 

 oil is 24J. (yd. per cwt. or is. per gallon. This is 



