HARDWICKE'S SCIENCE-GOSSIP. 



273 



M. ]\Iiquel found 750,000 living bacteria in a block 

 of ice from Lac de Joux, which had been kept for 

 eleven months, and that atmospheric microbia resisted 

 thirty-six hours' exposure to a temperature of— 100° C. 

 and revived in three days. The difference at the 

 different elevations must be due to the rarity of the 

 atmosphere. It is evident that these microscopic 

 creatures fall through thin air as the feather falls 

 through that in the air pump receiver in the well- 

 known guinea and feather experiment. Those who 

 still cling to the desperate theory of the suspension 

 of the dust of Krakatoa should ponder on this. 



The editor of the "Journal of Science" contends 

 that the failure of tha attempts to promote scientific 

 education in China is mainly attributable to the 

 system of literary examination there prevailing. 



Official employment and social rank are made 

 dependent on these examinations, and such rank 

 being the sole and universal ambition of the Chinese 

 people, Chinamen should be superlatively intellectual 

 if examinations have any educational value. Chinese 

 examinations are no sham, but are so severe that 

 " only a minority of the candidates pass, the plucked 

 ones coming up year after year, even to old age." 

 Mere memory of the lowest order, i.e. memory of 

 words, is so extravagantly cultivated that the rea- 

 soning powers of the men are as effectually crushed by 

 this wretched system of cerebral strangulation, as the 

 locomotive powers of the women are suppressed Ijy 

 the crippling of their feet. 



Among the books presented during the current 

 year to the Royal Astronomical Society is a transla- 

 tion of Sir John Herschel's " Outlines of Astronomy " 

 into Chinese, by A. Wylie. The fact that this is the 

 second edition published at Shang-hai, appears to 

 contradict the above, but the probable explanation is 

 that its circulation is limited to the outlying regions 

 of China, where British commerce and British 

 influence is beginning to break up the ancient con- 

 servation of this typically conservative people. 



A paper by Professor Sachs, published in the 

 early part of the present year, in the " Arbeiten des 

 botanischen Instituts," vol. iii. of Wiirtzburg, des- 

 cribes some researches that must be interesting to 

 most of the readers of Science-Gossip. If fresh 

 tjreen leaves are immersed in boiling water for about 

 ten minutes, and afterwards in alcohol, their chloro- 

 phyll is extracted without rupture of the cells, and 

 the leaves become etiolated. In some instances more 

 or less of starch remains. This is readily detected 

 by immersing the blanched leaf in a solution of 

 iodine in alcohol. If there is much starch, the 

 cellular tissue of the leaf becomes blue-black, the 

 •venation being displayed as a pale network on a 

 dark ground. Wi.h less starch, the colour is paler ; 

 with none, only a yellow stain of iodine is shown. 

 Any amateur may thus repeat the interesting experi- 

 ments of Sachs, which show that the quantity of 

 iitarch contained in leaves varies with their exposure 



to light. If a part of a leaf is covered with tinfoil, 

 and the rest is exposed to sunlight, the darkened 

 patch is displayed as a light patch, when the leaf has 

 been treated as above. 



The differences between the condition of the leaves 

 in the day and in the night is very strikingly shown, 

 and variations during the day may be thus demon- 

 strated, a very short time effecting the formation or 

 disappearance of the starch. Leaves full of starch in 

 the evening may be found quite empty in the morn- 

 ing. This is best shown by halving a given leaf in 

 the morning, and another in the evening, removing 

 the one half, and comparing the halves on the follow- 

 ing evening and morning. The half leaf separated 

 before sunrise and tested shows no starch, the re- 

 maining half tested in the evening displays much 

 starch. The difference is explained by the conversion 

 of the starch into soluljle glucose which is carried 

 away to nourish the plant. This occurs both during 

 day and night, but in the day more starch is formed 

 than is carried away. During the night no starch is 

 formed. Thus it happens that the composition of a 

 given leaf varies according to the hour of the day on 

 which it is plucked, and this may account for the 

 discrepancies observable in different analyses of the 

 leaves of the same plant. 



The further quantitative researches of Sachs have 

 led him to the conclusion that the formation of as 

 much as 20 to 25 grammes of starch is commonly 

 formed daily, per square metre of leaf surface (i oz. 

 avoirdupois is ==283 grammes). The quantity varies 

 with different plants. 



In the Proceedings of the Royal Society of Tasmania 

 for 1883, is a paper by E. T. Higgins, and W. F. 

 Petterd on a new cave spider {Theridion troglodites), 

 the female of which measures six and a half inches 

 from the claw of the anterior, to the claw of the 

 posterior leg. It is found in a cave in the Chudleigh 

 district. We are told that no insects have been 

 discovered in this cave, and that mammalian remains 

 are agglutinated in the rock by stalactitic incrusta- 

 tions. My own experience leads me to ask whether 

 the explorers looked for fleas as the possible food of 

 these spiders. I have found fleas in limestone caverns, 

 or, rather, they have found me, where no other 

 supplies of food existedj excepting the animal matter 

 that may have remained in the fossils of which the 

 limestone was chiefly composed. The most impres- 

 sive instance of this kind was in a very extensive 

 cavern, near Syracuse, that had long been closed, but 

 which, for want of better occupation, I attempted to 

 explore, in company with a guide and fellow tourist. 

 We were driven out of the cavern by an overwhelming 

 force of these creatures ; compelled to strip in the open 

 fields, shake each garment separately, then run twenty 

 or thirty yards away, and deposit it at this distance 

 from the shaking place and when all had been thus 

 removed go there to dress. Our guide "Jack 

 Robinson," an old Anglo-Syracusan sailor, estimated 



