548 



SCIENCE 



[N. S. Vol. LI. No. 1326 



others, for example Cape Cod, and in fact the 

 entire Atlantic coast, drifts easier with the 

 wind and is less stable unless indeed it is 

 stabilized by growing vegetation. A rough 

 sieve analysis gives the following proximate 

 physical composition, the percentages shown 

 being the amoimts passing or retained on 

 sieves of the indicated mesh. 



PHYSICAL ANALYSIS LAKE MICHIGAN SAND 



Shore Sand Dune Sand 



Einer tlian 100 mest . . 3.3 3.4 



Finer than 80 mesli 9.4 11.3 



Pinex than 60 mesh 49.2 46.3 



Coarser than 60 mesh. . 50.8 53.7 



"When examined chemically the sand shows 

 no remarkable peculiarity with the possible 

 exception of a rather high percentage of cal- 

 cium which may be accounted for by the fact 

 that the native rock of the region is limestone 

 and the gravel of the boulder clay of the west 

 shore of the lake is composed largely of the 

 same rock. Analyses of the shore sand and 

 of the dune sand give results which are prac- 

 tically identical. The following analyses 

 were mad« in 1911.^ 



CHEMICAL ANALYSIS OP SHORES AND DUNE SAND 

 Sliore Sand Dune Sand 



Loss on ignition 1.00 0.90 



Silica 92.00 91.90 



Iron and Al. oxides. . . 3.24 4.30 



Oaloium oxide 1.36 1.36 



Magnesium oxide .... 0.56 0.72 



Sodium oxide 0.47 0.63 



Potassium oxide 0.85 1.00 



Another analysis of sand from a blowout 

 was made in 1918 and gave the following 

 results : 



ANALYSIS OF SAND FROM BLOWOUT 



SiHca (SiOj) 90.28 



Iron oxide (FeA) 1-03 



Aluminum oxide (ALO3) 3.55 



Calcium oxide (OaO) . . ■. 1.57 



Magnesium oxide (MgO) 0.73 



Sodium oxide (Na,0) 2.22 



Potassium oxide (K,0) 1.05 



Phosphoric anhydride (PaOj) trace, less than 0.01% 



5 Analyses by L. S. Paddock. 



Approximately 90 to 92 per cent, of the 

 sand is silica but it should be remembered 

 that the remaining 8 to 10 per cent, consist- 

 ing of calciimi, magnesium, iron, aluminium, 

 sodium, potassium, etc., is contained in un- 

 decomposed silicate minerals. Under the 

 hand lens, while the clear white, yellow or 

 red sand quartz grains greatly predominate, 

 there is present also, in characteristic fashion, 

 a considerable proportion of bright-colored 

 and dark particles, red, brown, green and 

 black feldspar, mica, hornblende, magnetite, 

 etc., making up, let us say, approximately 25 

 per cent, of the total. From these particles 

 the dune plants must in the main derive their 

 supply of soluble inorganic substances nec- 

 essary for nutrition. It should be noted that 

 these rock particles are practically in their 

 unaltered condition, any decomposed or finely 

 disintegrated portions having been mostly dis- 

 solved or washed away by the waves or blown 

 away by the wind. However, when the sand 

 is agitated with water there is always present 

 a very small quantity of colloidal particles or 

 clay which is undoubtedly important for the 

 growth of plants. The amount, however, is 

 so slight that it scarcely fails to leave the 

 water clear and could be entirely disregarded 

 for the purpose of the argument. 



The integration of chemical infinitesimals 

 by the living organism is not an isolated or 

 unique phenomenon, particularly in the vege- 

 table world. It is nevertheless a matter of 

 the greatest interest, whether it consists in 

 the elaboration of complex carbon compounds 

 from the carbon dioxide of the atmosphere, 

 wherein this substance occurs at a dilution 

 of about 3 parts in 10,000, or the concentra- 

 tion of potassium salts by the giant kelps of 

 the Pacific {Macrocystis, Pelagophycus, Nereo- 

 cystis, etc.) from sea water which contains 

 about 4 parts potassium per 10,000 or only 

 about 1/30 the amount of sodium present; 

 but in the two instances cited, the raw mate- 

 rial is brought to the plant in suitable quan- 

 tity and form of combination, if in a condi- 

 tion of great dilution, from the enormous 



