Notices of Memoirs — Prof. Beecher — Cambrian Fossils. 559 



understand, is included under the head of chlorides, and calculated 

 into common salt would furnish 43 per cent, of the 16,657 tons. 

 It is cyclic of long period, and not available for Professor Joly's 

 calculation. 



Fluctuations. — An inverse relation undoubtedly exists between 

 the soluble contents of a river (including, of course, sodium 

 compounds) and the amount of water in it in Summer and Winter. 

 In all the great rivers subject to flood the variation must be 

 enormous; in the case of the Nile it amounts to 400 per cent. 

 As far as I can learn, these fluctuations have not been taken into 

 account. 



Coming once more to the numerator : Mysteries hang over it. 

 The composition of the sea is not what one would expect with the 

 precise conditions of solvent denudation required by Professor Joly's 

 speculations. For instance, one looks for huge proportions of nitrate 

 in it ; sea analyses show practically none. Again, the chlorine in it 

 multiplied by a known factor is a measure of its sodium contents, 

 but the same factor does not apply to average river water. These 

 are not matters of opinion but of fact. What becomes, then, of 

 Dr. Joly's " constancy in the nature and rate of solvent actions 

 going on over the land surfaces " (Trans. Eoy. Soc. Dublin, ser. ii, 

 vol. vii, p. 24) ? 



Too much space and time would be required for me to deal with 

 the second half of Professor Joly's November article. I may, 

 however, be permitted to observe that he appears to me to tilt at 

 an irrefragable law of solution, and then only saves his lance from 

 being utterly shattered by an adroit swerve. 



I. — Note on the Cambrian Fossils of St. Francois County, 

 Missouri. By Professor C. E. Beecher.^ 



rpHE small collection of fossils submitted to the writer by F. L. 

 J_ Nason, for identification, is interesting, especially as it determines 

 the geological horizon of an extensive series of limestones, sandstones, 

 conglomerates, etc., in south-eastern Missouri, the age of which has 

 hitherto been somewhat in doubt. Also, since these strata are 

 intimately associated with the lead-bearing rocks of this region, the 

 identification has considerable economic value. 



It is stated by Arthur Winslow, in a paper on " The Disseminated 

 Lead Ores of South-Eastern Missouri " - (p. 11), that although these 

 rocks are placed in the Lower Silurian " The possibility still remains 

 that there may be a faunal break which will admit of some of the 

 lower strata being classed as Cambrian, though there is nothing in 



' Reprinted from Silliman's American Journal of Science for November, 1901, 

 pp. 362-366. 



2 Bulletin No. 132 of the United States Geological Survey, 1896. 



