1902-3.] The Pal^ochemistry of the Ocean. 555 



potassium. With regard to this element it may be said that active living 

 matter has the power of absorbing it in large quantities and disposing 

 of it in an inert form by precipitating it at the peripheries of cells or in 

 inert organic masses within them, and, as a consequence, the ash of 

 animal and vegetable cells shows a larger quantity of potassium than the 

 protoplasm of the cells required. This illustrates how difficult it is to 

 determine the primitive and fixed proportions of potassium and calcium, 

 and further, how little we should depend, even in the case of muscle, 

 on the analyses of the ash of organs or organisms, for this purpose. If 

 a sufficient quantity of Amoebae* could be obtained for analysis it might 

 yield results of value but until that is done, the exact proportions of 

 sodium, potassium, calcium and magnesium must be a matter for con- 

 jecture. It can scarcely be that the proportions found in muscle repre- 

 sent even approximately those which should obtain in undifferentiated 

 propoplasm or cells.f 



VI. — Evidence frOxM the Lakes and Rivers of the Present 



Period. 



It may be pointed out that in the composition of the rivers, large 

 lakes, and seas of the world, there is evidence confirmatory of the view 

 that potassium and calcium predominated in the pre-Cambrian seas. 

 The conditions, of course, which contribute to the composition of the 

 lakes of to-day are not the same as those which existed when the 

 oceans of the globe were formed. There are but infinitesimal traces of 

 the chlorides of calcium and potassium in the rock crust or sedimentary 

 strata, and, further, there are, apart from the deposits of salt, and that 

 amount of it due to rainfall, but small quantities of sodium chloride 

 which can to-day come under the leaching action of water. There are 

 also soils to alter the proportions of the chemical elements derived 

 from them. 



Nevertheless it happens that in lakes surrounded, either wholly or 



* Fresh water, unicellular .initnal org-anisnis are apparently free from excess of the elements. They are, as 

 a rule, free from potassium, at least in such quantities as are found in other org-anisms. 



t According: to J. Katz (Pfluger's Arch., vol. 63, p. i), the proportions in muscle from different animals 

 are : 



Na. K. Ca. Mg. 



Man 100 400 9.3 26.4 



Dogr 100 354 7.26 25.1 



Rabbit 100 870 40.0 60.5 



Pike 100 1415 145.0 105.0 



These and other results of the same observer are open to the objection that no effort was made to gret 

 muscle fibre free from all adherent tissues. Visible blood vessels, tendons, nerves and fat were indeed re. 

 moved but these constitute only a part of the non-muscle portions of the tissue and they may be the cause of 

 the variations shown in the results. 



