194 



NATURE 



\yan. 4, 1872 



Prof. Wolf's law refers to the connection between A and B, 

 while our remark relers to B and C. We consider two successive 

 minima as the beginning and end of a single period, while M. 

 Wolf, at le.ist in this particular research, places the minimum 

 within the period, and compares the descent from the preceding 

 maximum with the ascent to the next one. 



We have considered the connection thus indicated of sufh- 

 cient importance to apply to it the following test. If, using the 

 previous notation, a definite relation exists between A and B, the 

 -ratio of the times which the events occupy in every epoch ouL^ht 

 to be approximately constant ; similarly with respect to B and C ; 

 and this ratio should not be influenced by tne absolute duratimi 

 of the two successive events. It is clear that the greater unifor- 

 mity of these ratios will be a test of their interdependence. 

 The following is the result of the comparison : — 



a. Prof. Wolf's law : comparison of A and B. 



PmnrU Duration of p„,;„rl^ Duration of 



l-eriods. descent (A). Fcnod^. ascent (B). 



I. :82g-5 to i833'8 4-3 years i833'8 to iS37'2 3^4 years. 

 II. i83y2 to 1844 o 6'8 ,, 1 844 'o to 1846 '6 2'b ,, 

 III. 1846-6 to 1850-2 96 ,, 1856-2 to 1 860 2 4-0 ,, 



Ratio ^. Difference from mean. 



I. 1-265 / ( -O-72S 



II. 2-615 (• Mean 2-093 +0-522 

 III. 2-400 ) ( +0-307 



These differences from the mean are so considerable that in 

 the present state of the inquiry a connection between any descent 

 and the immediately s/iiYii'i/iiij^ascenl appears highly improbable. 

 A very new atid apparently important relation seems, however, 

 to result from a similar comparison of any ascent and the imme- 

 diately succeeding descent, or between B and C. 

 ti. Comparison of B and C. 

 ,, . . Duration of n • i Durat'oii of 



f'^""'^*- ..scent (B). ^"'°'^>- descent (C). 



I. i833-92tol836'98 3 06 years 1836-98 to 184375 6-77years 

 II. i843-75to 1847-87 4-12 „ IS47-S7 to 1S56-31 8-44 ,, 

 III. 1856-31101859-69 3-38 ,, 1859-69 to 1867-12 7-43 ,, 



Ratio -?. Difl'ereiiLe from mean . 



b 

 I. 2-212 1 ( +0-061 



II. 2-044 -Mean 2'i5i ! — 0-107 

 III. 2-198 ) ( +0-047 



I'ROR AGASSIZ'S EXPLORING EXPEDITION* 



■VATE have already announced the departure of the United 

 • ' States Coast Survey exploring steamer, Ilasslcr, upon 

 that scientific mission which, under the direction of Prof Agassiz, 

 will doubtless be productive of very important results. Just 

 before starting on the e<peIition, Prof. Agassi/, addressed a com- 

 munication to the Superintendent of the Coast Survey, in whicli 

 he ventured to assume the character of a prophet by stating in 

 advance what it was probable would crown their efforts in the 

 way of discovery. 



The Professor makes this communication in the hope of show- 

 ing within what limits natural history has advanced toward that 

 point of maturity when science may anticipate the discovery of 

 facts. Basing his expectations upon the ascertained principles of 

 science, and taking into consideration the relationships between 

 different forms of animal life, and the succession of geological 

 epochs, and in view of the very interesting results of later deep- 

 sea dredging expeditions in the North Atlantic, he anticipates 

 the discovery, '-from the greater depth of the ocean, of repre- 

 sentatives resembling those types of animals which were promi- 

 nent in earlier geological periods, or bear a closer resemblance to 

 younger stages of the higher members of the same types, or to 

 the lower forms which take their place nowadays." 



Making no suggestion in regard to mammals, he remarks that 

 if reptiles exist in the deep waters, they must be only such as are 

 related to the extinct types of the Jurassic periods, such as the 

 ichthyosauri, plesiosauri, and pterodactyles ; but even of these 

 he thinks there is very little probability that any representatives 

 are still alive. 



Among the fishes he expects to discover some marine repre- 

 sentatives of the order of ganoids of the principal types known 

 from the secondary zoological period. Among the sharks he 

 thinks he shall find new forms allied to Cistracioii, or Hyhodou, 



* Reprinted from advance sheets of Harpci^s Weekly^ by permission of the 

 Editor. 



or Odonlaspis, as also new genera of chim.vroids ; and among 

 ordinary fishes the allies of Boyx, Elops, &c. It is among the 

 molluscs and radiates that objects of the greatest interest will 

 probably be met with : and chief among these will be nautiloid 

 cephalopod-s — perhaps even ammonites — and forms only known 

 hitherto in the fossil state. Among Accphala he anticipates the 

 discovery of a variety of forms resembling those from the Jurassic 

 and Cretaceous deposits ; while Riidistes will take the place of 

 oysters, and brachiopods be found very abundant. 



Among Crustacea it is not at all impossible that forms may be 

 fotmd resembling trilobites ; while among echinoderms lie con- 

 fidently expects to meet with spatangoids approaching Holaster, 

 and others akin to Dysasicr, &c. 



A careful comparison of the meinbers of the deep-sea fauna' of 

 the northern and southern hemispheres will probably prove of 

 the greatest interest, and, judging from the peculiarities of the 

 land and shore fauna of Australia, it is likely that the adjacent 

 deep-sea animals will be equally divergent, and will represent 

 remarkable forms, and especially of an extremely antique type. 



The Professor also hopes that much light will be thrown upon 

 the subject of the geology of the southern hemisphere, and upon 

 the general features of the drift, since all the phenomena related 

 to the glacial period must be found in the southern hemisphere 

 with the same essential characteristics as in the northern, yet with 

 this difference, that ever)'thing must be reversed ; that is, tiie 

 trend of the glacial abrasion must be from the south northward ; 

 the lee side of the abraded rocks must be on the north side of 

 hills and mountain ranges, and the boulders must have been 

 derived from rocky exposures lying to the south of their present 

 position. This point, however, must be established by obser- 

 vation. The Professor thinks this will be found to be the case, 

 with the exception, perhaps, of the present glaciers of Tierradel 

 Fuego and Patagonia. 



In reply to the possible inquiry as to what the question of 

 drift has to do with deep-sea dredging, he remarks that the con- 

 nection is closer than may at first appear. If drift is not of 

 glacial origin, but the product of marine currents, its formation 

 at once becomes a matter for the Coast Survey to investigate ; 

 but he expresses the belief that it will be found that, so far from 

 being accumulated by the sea, the drift of the lowlands of Pata- 

 gonia has been worn away to its present extent by the continued 

 encroachment of the ocean, in the same manner as the northern 

 shores of South America and of Brazil have been. 



SCIENTIFIC SERIALS 



A:iuahn dcr C/icmie uud Pharmacic, clix. , August 1871. Fittig 

 and Remsen communicate a second paper " On the Constitution 

 of Piperine and its decomposition products, Piperic Acid and 

 Pipendme ;" in the former paper two oxidation products were 

 described, piperonal and piperonylic acid, which stand to each 

 other in the relation of aldehyde and acetic acid. In the present 

 communication several new reactions of these substances are 

 described. — The second note, "A Reaction of free Phenol- 

 hydroxyls," shows that the benzene derivatives, containing 

 hydroxyl associated with this nucleus, give colours with a 

 neutral solution of ferric chloride ; the intensity of the colour 

 produced seems to bear some proportion to the number of free 

 hydroxyl atoms, the more intense colours being produced by 

 bodies containing more than one hydroxyl. — A paper " On the 

 relations between the Glycerin and Allyl compounds," by 

 Huebner and Mueller foil iws. They show that the dichlor- 

 hydrin prepared by Berthclot's method is a mixture of two 

 isomeric bodies, one of which boils at 174" and can be obtained 

 in a pure state by the action of hydrochloric acid on epichlor- 

 hydrin, the other boils at 182° and is identical with dichlorallyl 

 alcohol. Both of these compounds yield allyl alcohol when 

 acted on by sodium in the presence of ether. Kraut and Popp 

 have found that if sodium amalgam containing 3 per cent, 

 sodium is placed in potassic hydrate solution, hard cubes are 

 formed, which, however, possess no definite composition ; by the 

 action of sodic hydrate solution long needles are obtained, having 

 the composition Na„ Hgi,. — A lengthy paper by flotfmeister fol- 

 lows "On Phenyl Ether and Diphenyloxide. " The former is 

 prepared by the action of nitrous acid on aniline sulphate, the 

 product from which is mixed with phenol when nitrogen is evohed 

 and phenyl ether formed. Ic can also be produced by the dry 

 distillation of cupric benzoate. Diphcnyl oxide is produced by 

 acting on phenol with phosphoric chloride, and again acting on 



