228 



KNOWLEDGE 



[Jak. 13, 1882. 



this 8ubji-ct to iioinn extent, nnd the rcsnit of their labours in that 

 they fiiitl in thoHo Htonns fo8*»il sponges, corals, and crinoids. They 

 are also of the opinion tliat tliey have discovered a trace of vopctable 

 remains. The best delined fossils aro tlioso of corals and sponfres, 

 and in rcj^ard to these there would seem to be no doubt. The 

 corals belong to clas.ies which on the earth are foun<l only in 

 some of the oldest geol<)),Hcal formations, and they differ from 

 onrs in being extremely small. Of the sponges, the remains were in 

 such excellent preservation, that " Dr. Weinland succeeded in actually 

 determining three genera. " 



*' Of one chanicteristic bluish sponge which occurred in several 

 favourable shavings (into which the stone was cut), both as young 

 and old specimens, he was able to make a drawing of its interior 

 construction as easily as from a living specimen." 



These startling discoveries i>oint to the fact that in the world 

 where these rocks and animal forms originated, the course of organic 

 evolution was very similar to that which has taken place upon our 

 earth. But these eminent savants are of the opinion that discoveries 

 will yet be made of organisms for which no place can be found in 

 our systems of zoology. The petrifactions all belong to the sub- 

 aqueous classes of animals of the lower and more ])rimitive forms, 

 and up to this time no trace has been found of any higher animals, 

 as mollusks, &c. 



Dr. Hahn has published a book giving an account of this won- 

 derful discovery, which is illustrated with engravings of more than 

 one hundred specimens of these organic remains, no two of which 

 are alike. These have been reproduced by photography, which docs 

 not lie. Further investigations in this new and untrodden field of 

 research will be awaited with the most profound interest. — Chicago 

 Herald. 



DURATION OF LIFE. 



AX article lately appeared in the BritUh ifedirnl Jnuriial on 

 " Has the duration of Human Life in England increased 

 during the last thirty years ? " by Dr. Rabagliati. I have con- 

 densed most of it for jour readers. From 1838-40, the average 

 death-rate was 22-3 per 1,000; in 1876-9, it was 21 per 1,000; or 

 an average of -l-iy years agaiii.st 47'6 years ; this gives an addition 

 of 2"8 years to each one's life. If our population is 25,7y8,922 

 people in Great Britain, then 72,236,981 years of life are added to 

 a generation. 



The improvement, he says, is due to better ventilation and 

 drainage, less overcrowding, the destruction of fever dens, &c. This 

 addition, when analysed, shows that infant life is more certain, 

 whilst males above 35, and females above 45 are dying faster than 

 thirty years ago. 



Between 1851 and 1878, 3605 male children under five ye.ars died 

 ]ier 1,000; in 1879 only 3195 per 1,000; this is an addition of 

 11'4 per cent, to life. If we still compare these dates we find that 

 between Sand 10 years, 19 per cent, was added ; 10 and 15 years it 

 was '24 -i i)er cent. ; 15 and 20 years it was 220 per cent. ; from 

 20 to 25 it was 22'6 per cent. ; from 25 to 35 years it was 113 per 

 cent. In females, comparing same data, it was 141, 22'4, 24"4, 

 254, 237, 167 ; and from 35 to 45 years there was a saving of 

 5'8 per cent, in 1879. Males in 1879 from 35 to 45 years died 

 15 per cent, faster than before ; 45 to 55 years, 26 per cent, 

 faster ; 55 to 65 years, 11'9 per cent. ; 65 to 75 years, 7'8 per cent., 

 and above 85 years, 7 l>er cent, faster than from 1851 to 1878. 

 Females between 45 to 55 years 6 or -jSj per cent, died faster ; from 

 55 to 05 years, 12-2 per cent.; 05 to 75 years, 116 per cent.; 

 75 to 85 years, 95 per cent. ; above 85 years, 48 per cent. 

 <lied faster. Examine, then, every 10 years and wo find 

 in 1841 to 1850 the death-rate was 22-4" per 1,000; 1851 to 

 1860 it was 222 per 1,000; 1861 to 1870, it was 225 per 1,000; 

 nnd from 1871-9 (nine years) it was 21-5 per 1,000. The 

 improved rate of health has taken |)lace since 1870. Deaths 

 from zymotic (infectious) diseases have lessened ; thus from 1850 

 to 1854 they were at the rate of 5,231. per million living people; 

 1855 to 1859, they were 5,039 per million ; 1860 to 1864, they were 

 4,899 per million ; 1865 to 1869, they were 5,172 per million'; 1870 

 to 1874, they were 4,849 per million ; 1875 to 1879, they were 3,911 

 per million of living beings. From 1850 to 1854 the death-rate was 

 high from these causes ; in 1877 to 1879 it was lower from them ; but 

 from other causes it was higher than from 1850 to 1854. minus these. 

 Thus it sccm.s that in those days the people were healthier than our 

 present race — it was a ca.se of survival of the fittest, the weakly 

 ones then died and .so increased infant mortality ; now the weaker 

 ones live, and die soon aft<?r manhood, and swell its mortality, in- 

 stead. The diseases that attack young lives are also becoming less 

 fatal, such as scrofula and consumption, whilst diseases of more 

 ivdvanccd life arc, on the other hand, increasing in fatality, such as 



cancer. 'ITiis reads us a terrible lesson, and one to which everyono'* 

 attention shfiuld be drawn, for we undoubtedly hold our lives in our 

 own hands ; so it depenrls with ourselves, in a great measure, 

 whether wo die at 35 or 75 years. 



T. li. Ai.LiN.-o.\, L.R.C.P. 



KNOWLEDGE FOR THE YOUNG.* 



AN idea seems to prevail that the best way to make knowledge 

 palatable to the young, or to beginners generally, is to dilute 

 it : if a reader finds one fact in a page ho can digest it, and better 

 still if ho finds one fact in half-a-dozen piigcs. Then, again, many 

 imagine that knowledge must be sweetened to suit the taste of 

 young folks : we must be poetical and use flowery lacgnage, or 

 they will turn from knowledge in disgust. We believe all this (we 

 may say we know it) to be entirely erroneous. If it were true, the 

 book before us would be utterly unsuited for young people ; but, as 

 a matter of fact, it is just the sort of book they want. There is no 

 poetry, no flowery language, no attempt to interest by fine talking ; 

 and yet the book is full of interest from cover to cover, and full of 

 poetry, too, for those who can read between the lines. Take the open- 

 ing words. " Coal. — When wood or woody matter such as roots, bark, 

 leaves, moss, peat, and so on, lies buried in the earth for a very 

 long time, it changes into coal. Wherever coal is now found, there 

 were once forests, or woods, or peat, or else mouths of rivers or 

 other places where plants grew, or their dead parts, or leaves, or 

 branches, and roots got heaped together. Then such places get 

 covered with water, often because they sank below the level of the 

 sea, and the sea covered them, and they were at the bottom of the 

 sea. Then the mud which rivers bring down to the sea sank down 

 and covered them, and the shells and skeletons of dead sea animals 

 fell also upon them, so that they got covered deeper and deeper." 

 Then the later stages of coal formation are described, without a 

 wasted sentence. And at the foot of the second jiage the coal has 

 been followed to ashes, cinders, coke, and breeze (broken up coke), 

 and so the first chapter ends. 



How much more sensible tliis than a page or two of pretty talk 

 about the cheerful blaze of our home fires, the comforting warmth 

 of stoves, and so forth, followed by vague mention of the work coal 

 does in manufacture, &c., with then, perhaps, a reference to the 

 forest primeval, and poetical picturings of the work done by river 

 and sea. We have before us a work, on another subject, in which 

 just such a course is followed. Six pages are employed in saying 

 what might very well be said in half a page, aud then the author 

 has the face to say, " let us recapitulate ", — the reader being all the 

 while treated as a child might be to whom a bitter medicine was to 

 be given in a spoonful of sweetstuff. 



Now, children as a rule (though elementary books arc best 

 WTitten when not specially meant for children) care very little for 

 poetical descriptions, and a great deal for facts. They often find a 

 good deal of poetry in the facts ; indeed, we can imagine few better 

 lessons for tliose who want to jiut poetry into their science books 

 than to tell their facts to a bright child, and to listen to its com- 

 ments. If you want thoroughly to interest a child you must not 

 dilute, but condense. An intelligent child's digestive capacity for 

 information is greater (not less, as many fondly imagine) than that 

 of most grown persons. The usual way of treating readers of 

 " first books " is as unwise as would be the use of baby food for 

 growing boys. 



Let parents try the experiment. Give a boy a so-called scientific 

 book full of poetry and platitudes, with the science disguised out of 

 all knowledge, and note how he will weary of it. Then give him 

 such a book as Professor Guthrie's "First Book of Knowledge," 

 and see how much the lad will prefer good meat to pap. Some 

 reviewers criticise such books as this on the score of what they call 

 a common-place style, not knowing that the true eloquence of the 

 scientific writer resides in clearness and plainness of speech. So 

 judged. Professor Guthrie's style is excellent. 



The subjects dealt with in this capital book are classed onder 

 the following heads : — " Things and Stuffs used for Honse- 

 building. The Elements, Wood, Heating and Lighting, Finishing 

 and Furnishing (of houses), Clothing, Food, Cleaning, Writing, 

 and Printing." There are questions at the end of each chapter, 

 Imt wo believe that what is learned for i|uestion - answering is 

 not properly learned at all. A clever boy should take such a 

 book as this for the mere pleasure of satisfying the mental 

 craving (natural in all healthy minds) for information, — which is 

 the mind's plain food. 



• " The First Book of Knowledge." By Frederick Guthrie, F.R.S. 

 (Marcus Ward iS: Co., London.) 



