NATURE 



{^Aiigust 26, 1880 



Some of the last chapters of this excellent work arc 

 specially rich in information and suggcstiveness. That 

 on "Will and Voluntary Movements" deals lucidly with 

 a difficult subject ; and the chapters on " Speaking, 

 Reading, and Writing," and on " The Cerebral Relations 

 of Speech and Thought " contain much valuable informa- 

 tion regarding the physiology and pathology of intellectual 

 expression and the light which they throw upon the nature 

 of mind as a function of the brain — a phrase which must 

 be read subject co the explanation which Dr. Bastian 

 gives of the title of his work. There may be some reason 

 to doubt whether transcendental metaphysicians will be 

 prepared to admit that their belief in mind as an entity 

 has been so completely destroyed, as Dr. Bastian thinks, 

 by the demonstration of the doctrine of unconscious 

 cerebration and the consequent vitiation of all deductions 

 drawn exclusively from within the range of consciousness; 

 but there is no room for doubt that metaphysicians of 

 all shades must make themselves familiar with such 

 researches as those embodied in Dr. Bastian's work. 

 Should they fail to do so they must be prepared to find 

 their carefully-nurtured speculations exposed to many 

 severe rebuff's, and open at all times to that kind of 

 merciless danger which theories experience when they 

 run against conflicting facts. 



This work is the best book of its kind. It is full, and at 

 the same time concise ; comprehensive, but confined to 

 a readable limit ; and though it deals with many subtle 

 subjects it expounds them in a style which is admirable 

 for its clearness and simplicity. 



LETTERS TO THE EDITOR 



[The Editor does not hold himself responsible for opinions expressed 

 by his correspondents. Neither can he undertake to return, or 

 to correspond with the ivriters of, rejected mamiscripts. No 

 notice is taken of anonymous commiotications. 



[ The Editor urgently requests correspondents to keep their letters as 

 short as possible. The pressure on his space is so great that it 

 is impossible otherwise to ensure the appearance even of com- 

 mu>iications containing interestins: and noi'el facts.'\ 



Eozoic and Palasozoic 



Permit an old worker in fos.siIs to protest mildly against the 

 .slapdash manner in which writers sometimes hit off great 

 palreontological questions. In your review of Roemer's valuable 

 " Lethsa Palajozoica" it is stated that in regard to Eozoon 

 canadense, he ' ' accepts the verdict of Mobius against its organic 

 origin, and rejects it from the list of pateozoic fossils." Now 

 as to the acceptance of the ' ' verdict " in question, I have nothing 

 to say, except that the naturalist to whom are assigned the 

 functions of judge and jury in the case very obviously lacks 

 some of the qualifications for that high office, and has not been 

 recognised by those best qualified to understand the case of 

 Eozoon. But why Roemer or your reviewer should "reject Eozoon 

 from the list of palaeozoic fossils " I am at a loss to understand. 

 As a writer on paleozoic fossils, Roemer has nothing to do with 

 Eozoon. It belongs to that great series of eozoic or archsean 

 formations which precedes the paljeozoic, and which probably 

 represents quite as long a period. Little comparatively is known 

 of the fossils of these oldest rocks ; but what we do know of 

 their Eozoon, Archaospherincc, Spiral arenicoHtes, and Aspi- 

 ddla, and of their immense deposits of graphitised plants, 

 is sufficient to assure us that the life of the eozoic period was 

 very different from that of the palceozoic ; Eozoon, whatever 

 its nature, is one of the most characteristic of these eozoic 

 fossils. It has been recognised through a great vertical thick- 

 ness of beds, and over so wide areas, that it is now equally 

 characteristic of eozoic rocks in Canada and Brazil, in Bavaria 

 and in Scandinavia. Further, it has obviously been connected 

 wiih the accumulation of some of the greatest limestones of 

 the eozoic time. 



One can excuse a paljeontologist familiar only with mesozoic 

 or kainozoic fossils, when h« doubts as to the organic nature of 

 such obscure markings as Oldhatnia, or even as to those wrink- 

 lings and scratchings on Cambrian slates which are recognised 

 as trilobites and sponges ; but we never think of asking him to 

 accept or reject them as mesozoic fossils. In like manner tho;e 

 who are working out the dim traces of life remaining in the 

 eozoic rocks will be content if geologists who scarcely conde- 

 scend to recognise these great formations in their arrangements 

 will abstain in the mean time from pronouncing judgment on 

 eozoic remains supposed to be organic. 



To us in Canada who have long regarded the eozoic forma- 

 tions as being quite as important in a physical point of view as 

 the palaeozoic, it is a matter of congratulation that they are no.v 

 attracting so much of the attention of British geologists. Their 

 palaeontology, it is true, is still meagre, but our knowledge of it 

 is gradually increasing, and those who have lived to see the 

 Cambrian fauna grow from nothing to its present satisfactory 

 condition need not despair of the Laurentian or Huronian. 



Montreal, August 5 J. W. Dawson 



Algae 



I NOTICE in Nature, vol. xxii. p. 319, that amongit other 

 subjects you answer inquiries about minute "algje." 



I venture to send you herewith specimens of one of the Oscil- 

 latoriacea:, which I believe is rare. In form it is nearest to what is 

 Jecribed in the " Micrographical Dictionary " as '^ Spirulina 

 oscillaroides " (Tur|i. ?), but it is very much larger. When two 

 join and intertwine they form a cable. Under an ^th objective it 

 is a most striking object ; it has the characteristic deep blue- 

 green colour, and also its movements. 



I shall be glad to know if it has been described by any one. 

 G. F. Chantrell 



St. James's Mount, Liverpool, August 6 



[The alga is Spinilina jenneri, Kutz, and the Spirillum jenneri, 

 Ilassall. It is described in the " Fresh Water Alga; " of the 

 latter author, and the description occurs also in Rabenhorst's 

 " Alga; aquK-dulcis." 



During this year, in a paper read by the Rev. J. E. Vize at the 

 Montgomery Society, and printed in their Proceedings, it is 

 called Spirulina oscillarioides, but it is larger, and more distinctly 

 articulated than that species. The figure given by Mr. Vize is 

 accurate. It is not very common, but we have heard of it in 

 two or three localities during the past twelve months. — Ed.] 



Lightning Conductors 

 I shall feel exceedingly obliged if you will have the kindness 

 to reply to the following question : — Thepainterof my villa (Villa 

 Calpe) having taken the liberty to paint the chain of the lightning 

 conductor attached to my house, I should like to know whether 

 it « iU mterfere with the efficiency of the apparatus. 



Catherine McPherson de Bremon 

 Biarritz, August S 



[A coat of paint on a lightning conductor will not at all affect 

 its efficiency. It will protect it from rust, which of course is an 

 advantage. But if the note is to be read literally and a chain is 

 used as a conductor, it is the w orst possible form, and it ought 

 to be changed for a continuous conductor. The links of a 

 chain only touch each other at points, so that even a link made 

 of half an inch in diameter of metal is reduced to the size of less 

 than yV of an inch of metal. W^e would rather trust to a copper 

 w ire of yV than to a link of much larger size. A point of great 

 importance is to have a good discharge in the earth, either wet 

 soil or a large quantity of metal joined to the conductor. — Ed.] 



Strange Method of Crossing a Torrent 

 Referring to the inquiry of your correspondent as to the 

 existence in modern times of the practice of carrying a stone to 

 steady oneself whilst crossing a ton-ent, I may state that it is 

 well known to the inhabitants of mountainous districts, and 

 though practically it may not often have to be resorted to in 

 Switzerland, where the streams are mostly well bridged, 1 have 

 myself been glad to adopt it in Dauphine. As, however, a 

 weight on the head or shoulders would, by raising the centre of 

 gravity, rather diminish than add to the steadiness of the bearer, 

 it is more usual to fill the lower side pockets of the coat, and per- 



