246 



SCIENCE. 



of articles* on the subject of cohesion and the atomic 

 theory, the latter of which he attacks with all the acnteness 

 we are wont to find in his writings. 



In regard to Mohr's Gesehichte der Erde, which he rightly 

 calls : Geology on a new basis, it is impossible to say little, if 

 it should be spoken of at all. Suffice it, however, to state that 

 it is not what is usually called Neptunism what Mohr advo- 

 cates ; it is free from any kind of " ism," as the man who 

 wrote it himself was. But in the generally accepted plutonistic 

 geology, fire plays such an omnipotent role, that any deviat- 

 ing view, any appreciation of the true state of things geo- 

 logical, is believed to deserve that name from the outset. 

 The so-called Neptunism of Mohr has, however, nothing 

 in common with the impossibilities of the Old Neptunistic 

 School of Werner and his followers. 



There is this radical difference between the views, as yet 

 generally accepted, and those advanced by Mohr : 



His aim is to show in what manner 'the several minerals 

 and rocks, composing the outermost, accessible strata of 

 our earth, have been formed ; the question of time he consi- 

 ders to be not only irrelevant, but also very difficult of as- 

 certaining. His firm conviction of the falsity of the nebular 

 hypothesis and the previous fluid state of the earth and the 

 present molten state of its interior has been strongly sup- 

 ported of late, not only by other savants, but by a number 

 of facts and reasonings. The foremost among the former is 

 embodied in the results ot careful measurements of temper- 

 ature in the deep boring (4052 ) at Speremberg, near Berlin, 

 conducted by the most learned and experienced mining 

 officials of the Prussian Government. They show that the 

 old supposition of 1 C. increase of temperature to each 

 100' is fallacious, and that this increase diminishes con- 

 stantly in going down. Here is the table : 



I 



Temperature. 



I 



IS 6£4° 



Reaumur 



1.097c 



17849 





1.047 



19 943 





0.997 



21 937 





0.946 



23.830 





0.896 



25 623 





0.846 



'-*7 315 





0-79S 



28 906 





0.608 



3 6 75 6 







Increase per 100 ft. 



2.468° 



2-35° 

 2.243 

 2.128 

 2 018 

 I.904 

 1.789 

 I.368 



F. 



Depth. 



700 Rh. ft. i<5 6C4 Reaumur 1.097 R. 



900 

 1 100 

 1300 

 1500 

 1700 

 1900 

 2100 

 3390 



While for the lowest 100 feet it was : 0.445 R. (1.001' F.) 



"This would make the final result, as stated by Mohr," 

 says Dr. Klein,* " very well founded, nay, indisputable, 

 viz. : ' that the increase of temperature will cease altogether ,-' 

 not at a depth of 5000' or 6000', as Mohr will have it, but, 

 at all events, at a depth considerably below 100,000." 



Thus, in addition to the many astronomical, physical and 

 chemical reasons, which are irreconcilable with the nebular 

 hypothesis and with the theory of the molten interior of the 

 earth, derived from this hypothesis, Mohr has pointed out 

 an irrefutable fact which supports this position.** For, 

 continuing the slight increase found in a proportionate 

 ratio, at the point where there will be no more increase, the 

 temperature actually obtaining will fall much below the 

 melting point of lead ; this had been predicted by Mohr 

 on other grounds, before the measurements made at Sper- 

 emberg had been published. 



Chemistry, especially, is ingeniously applied to geology in 

 MOHR'S work, and from the chemical constitution and 

 physical properties of the various minerals and the rock- 

 formations which they compose, conclusions are arrived at 

 which throw a new light, in many cases, on the probable ori- 

 gin and subsequent metamorphosis of the various compo- 

 nent parts of the surface of our globe. I'o mention only 

 one important result, we may refer to the different properties 

 of tin- Silicate rocks having volcanic origin, as compared 

 with those having, until lately, been supposed to have a 



■\ 11 1. -i I- 11 ;" Vol. 1 1 . I ; 1 ; pp 13 



I In: rest ni this series which the editor of the Annate ft dc- 

 clined t'i publish, arc those mentioned in the f< ot-note on p. 203 of No. 



17 of this journal. 



* />/,■ /■<>> is, h 1 ittt der < | ' 7 5 .' /■ 57- 



** In a future article thi subject will be exhaustively treated, and the 



fiosition, taken by Vol 01 1 . Mom and \< idbnh \< >• \ in regard to thenebu- 

 .ir hypothesis, as well as thai 01 Sit William Thomson Pouli r, 



II Hi I othei in regard to the Earth's molten I" 



h tn hi ■! of and criticized V letter, also, from the 

 penofom '.1 Imeri will bt quoted, in which this emi- 

 nent nil bjei ' "i a manner w hii h add 1 thi 



additional weight of hi uperior authority to thi 1 id Iduced agaihsi 



this Hypothi G. wT R. 



' plutonic ' origin. The several properties which the one 

 kind possesses are not found to be properties of the other, 

 and Mohr, therefore, takes strong ground to deny their 

 fiery origin. 



Among these properties, demonstrating their crystalline 

 origin, may be mentioned the following : 



1. That Feldspar, Augite, Hornblende, Mica, Rock- 

 crystal, Quartz, etc., as well as the rocks which are com- 

 posed of these minerals, all show minute cavities contain- 

 ing water which are not found in rocks that have undoubt- 

 edly been molten, such as Obsidian and other lavas. 



2. That the specific gravity of the silicic acid contained 

 in them is greater (2, 5 — 2, 6) than that in volcanic rocks 

 (2, 5—2, 3). 



3. That by meltingthese crystalline rocks (Basalt, Granite, 

 etc.,) their specific gravity is reduced in the same proportion. 



4. That petrified wood, fossils, and other pseudomor- 

 phoses of organic origin, and even organic matter unchanged 

 (Asphalte in Granite), is found to be enclosed in them. 



5. That the crystalline rocks decay much easier and 

 quicker than the volcanic molten rocks. 



6. That many chemical actions, combinations, etc., would 

 be impossible if a molten condition was presupposed, etc. 



These and other properties of less importance undoubt- 

 edly form a strong array of proofs against the '■plutonic' or 

 fiery origin of the Silicate Rocks. 



The formation of lime-deposits takes place according to 

 Mohr in the ocean by the following bio-chemical processes : 



The sulphate of lime contained in the sea-water is assi- 

 milated by the marine plants (Alga and Fucks especially), 

 and by them decomposed in the course of their vital pro- 

 cesses. While the sulphur enters into albuminous com- 

 pounds, the lime unites with carbonic acid, and both go to 

 form part of the plant itself. The plants serve as nourish- 

 ment to the myriads of minute animals (Rhizopoda and Fora- 

 miniferd), which populate the oceans, and while the carbon- 

 ate of lime serves to build up their shell, the sulphur is 

 eliminated by their bio-chemical process as sulphurous and 

 hydrosulphuric acid. These shells which lie from 10 to 15 

 feet deep at the bottom of the oceans, are the chalk and 

 lime-beds of the future. 



The presence of organic matter in meteoritic masses and 

 the absence of carbon in meteoritic iron are pointed out by 

 Mohr as further proofs against the plutonistic and in favor 

 of the crystalline origin of the heavenly bodies. The chap- 

 ter on these mysterious visitors from the celestial spaces is 

 the longest and certainly one of the most interesting. 



His views, especially in regard to the constant metamor- 

 phosis of rock-strata, are in fair way of becoming generally 

 accepted — although his name is not as yet mentioned in 

 connection with them.* 



Another theory which refers the formation of coal-fields 

 to the deposition of immense masses of sea-weeds and 

 tangs at the bottom of the ocean, has been greatly sup- 

 ported by the discovery that Iodine and Bromine are re- 

 gularly found in the smoke-black from chimneys where 

 coal is burned. 



The book abounds in new and original researches 

 as well as in bold deductions ; and even those who do not 

 agree with the author will find in it an almost inex- 

 haustible source of information, and will experience that 

 great delight which the writings of a great thinker always 

 give to an impartial reader. 



In conclusion, it may be safely said that Mohr belonged 

 to those whose writings and the results of whose labors will 

 not lose interest as time passes, but will rather be more and 

 more generally appreciated. He has said or written but 

 very little that he was forced to revoke; on the contrary, 

 many of his views have stood against the attack of time 

 and of his adversaries, and many of the latter have been 

 forced to admit that he was right. 



Personally, as has been mentioned already, Friedrich 



Mom; was the most amiable of men, and the Editor ol the 



' Gaea,' Dr. H. Klein, who was a near friend of his during man; 



years, lightly says of him (in a private Idler to the writer): 

 " in every respect Mom; was a man who would be an or- 

 nament to any period ot Human History." 



• Strata of Shales, Mica-Schist, Calcareous Schist ami ilm-iss not in- 

 frequently are so uniformly spread out, in the same locality, that there 



1 .hi 1.1 mi doubl "1 1 inn ' minium origin, 



