rientifk Jtows 



FOR GENERAL READERS. 



Vol. II. 



OCTOBER 19, 1888. 



No. 16. 



CONTENTS. 



PAGE 



Scientific Table Talk 401 



Some Photo-micrographic Apparatus 



(Illus.) 402 



Ancient Inhabitants of the Canary 



Islands (Illus.) 404 



General Notes ... 407 



Curious Flint Instruments (Illus.') ... 409 



Formation of Petroleum 410 



Natural History — 



A Curious Fungus {Illus.) 411 



Ants and Butterflies 412 



Intelligence of a Cat ... ... — 412 



Cockchafers in Autumn ... ... 413 



PAGE 



• 413 



. 414 



The Sheep Fly 



Work for Naturalists' Clubs ... 



Reviews — 



Planetary and Stellar Studies ... 415 



Proceedings of the Bristol Naturalists' 



Society ... 415 



The Midland Naturalist 416 



Forest Culture and Eucalyptus Trees 416 



Abstracts of Papers, Lectures, etc. — 

 Yorkshire Association of Sanitary In- 

 spectors ... ... ... ... 416 



Woodhope Naturalists' Field Club ... 418 



PAGE 

 Cheltenham Natural Science So- 

 ciety ... ... ... ... 420 



Miscellaneous Societies 420 



Totem Clans and Star Worship .... 420 

 Correspondence — 



The Sparrow ... ._ .„ ... 422 



Recent Inventions 423 



Diary for Next Week 424 



Sales and Exchanges ... ... ... 424 



Selected Books ... ... ... ... 424 



Notices 424 



Meteorological Returns 424 



SCIENTIFIC TABLE TALK. 



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

 On page 262 of Scientific News is an abstract of a note 

 read at the British Association by the Rev. A. Irving, 

 D.Sc, on the " Relation of the Percentage of Carbonic 

 Acid in the Atmosphere to the Life and Growth of 

 Plants." According to experiments there referred to, 

 the vigour of plant life is increased by increasing the 

 supply of carbonic acid in the air up to about an equality 

 of the oxygen, i.e., to about 600 times as much as the 

 air at present contains, provided the roots are freely 

 supplied with water. 



This is a rather startling result, and so much opposed 

 to those of other experiments, that I am not surprised to 

 read on page 288 that Professor Seeley expressed some 

 scepticism, and referred to the fact that the surroundings 

 of lime kilns are not remarkable for luxuriant vegetation. 

 To this example I may add that of the celebrated Grotta 

 del Cane, from which there is a continual overflow of 

 carbonic acid pouring down the slope of the valley 

 towards the lake below. This is shown by immersing a 

 torch in the pool of carbonic acid. The torch is thereby 

 extinguished, but its smoke adheres to the heavy gas and 

 accompanies its overflow, thus rendering its course 

 plainly visible if the experiment be so performed as to 

 produce a good supply of smoke. There is another 

 similar outflow of carbonic acid shown in the same valley, 

 which, when I was there, bore the name of " the foun- 

 tain of natural beer," a name based on the experiment of 

 standing knee-deep in the gas and scooping draughts to 

 the mouth by the hand, thereby obtaining a taste similar 

 to that of the effervescing beverage known as " birra " to 

 the Neapolitans. The carbonic acid overflows abun- 

 dantly from this and other places in the neighbourhood. 

 If Dr. Irving is right, the course of all these streams should 

 be indicated by specially luxuriant vegetation, but such is 

 not the case. 



Another subject was opened by this paper, viz., the 

 assumed or supposed excess of carbonic acid in the car- 

 boniferous age. This supposition includes another, 

 which in spite of its wide and free acceptance, appears 

 to me to be a very superficial one. I refer to the matter- 



of-course assumption that at the time when our parti- 

 cular coal seams were in the course of deposition, all the 

 rest of the world was engaged in just the same kind of 

 geological business. 



We know that in certain areas certain deposits were 

 formed later than those upon which they rest, and earlier 

 than those above them ; but we have no evidence to 

 prove that similarity of composition of any particular 

 deposit, or even similarity of fossils, proved simultaneous 

 deposition all over the world. 



We do know, for example, that the fauna and flora of 

 Australia and New Zealand actually living there prior 

 to the interference of British colonisation, differed more 

 widely from the simultaneously existent fauna and flora 

 of Europe, Asia, and Africa, than do those revealed by 

 the fossils of the post-pliocene and pliocene, and even 

 earlier periods, and that they were more nearly allied 

 to these than to living species on our side of the 

 world. 



At the present time the lithological character of cur- 

 rent deposits varies with the rocks from which the de- 

 positing rivers obtain their material, or those of the 

 shores which the sea waves are wearing down. Besides 

 these variations we have glacial deposits and volcanic 

 rocks simultaneously in the course of formation, and we 

 have great peat bogs growing and ready for submersion 

 in some places but none in others. 



As I have shown (see " The Formation of Coal " in 

 " Science in Short Chapters "), we have coal seams now 

 in course of formation in the Aachensee and the fjords of 

 Norway, that have come under my own observation, and 

 doubtless in a multitude of other places where similar 

 conditions prevail. 



In the interesting account of the inhabitants of the 

 Canary Islands, by Mr. J. H. Stone (Scientific News, page 

 355), we have an example of the so-called " stone age " 

 {"stone stage" would be better) flourishing in modern 

 times. The same occurs in New Guinea. 



The deep sea explorations of the Challenger and other 

 expeditions have inflicted serious thrusts on the estab- 

 lished practice of determining geological time periods by 

 fossil fauna, living creatures having been fished up from 

 the deep sea which, had they been found as fossils, 



