MA.T 28, 1915] 



SCIENCE 



795 



the slightest intimation that its claims to 

 existence are any less valid than any other 

 compound. It is stated that the water in the 

 soil is weakly held, when as a matter of fact 

 the film moisture is held by probably enormous 

 stress and the reader is left in confusion as 

 to just what the author means. It is not the 

 simplest view (page 77) that the mineral par- 

 ticles are coated with a colloidal complex, but 

 that the so-called colloidal properties of the 

 soil are those resulting from the relatively vast 

 surface presented by the " clay " portion of the 

 soil; and it would be more satisfactory to 

 utilize the fact that the solubility of calcium 

 carbonate is increased by increasing the partial 

 pressure due to carbon dioxide than assume the 

 existence of a compound which can not exist 

 at any gas pressures existing in the soil. 



But when there is so very much that is ad- 

 mirable it makes one feel ungracious to con- 

 tinue criticisms of details. The book delib- 

 erately makes its major appeal to biologists, 

 and the greater part of the text is devoted to 

 the biological properties of the soil. But its 

 most striking feature is the skilful handling 

 of the contrasting views of soil chemists and 

 physicists. While it is probable that others as 

 well as the reviewer will not entirely agree 

 with the author's presentation of recent con- 

 troversies, every one will undoubtedly recog- 

 nize the evident intent of fairness and careful 

 effort to summarize correctly. It is very prob- 

 able that no one could at this time make a 

 better presentation than has Dr. Eussell, al- 

 though we may each hope that some future 

 edition of his book may accord more closely 

 with our several individual views. Fortu- 

 nately for the development of this branch of 

 applied science, modification of the personal 

 views of most of the prominent workers is 

 commendably frequent and frank. A satis- 

 factory index and a well-selected bibliography 

 are retained in the present edition. 



Dr. EusseU's monograph is not suited to 

 class-room use of undergraduates in our agri- 

 cultural colleges, though such undergraduates 

 would undoubtedly profit by reading it. The 

 book will prove a mine of suggestions to the 

 advanced scholar and investigator and should 



prove an eloquent testimony for the view that 

 the time has now come when our universities 

 can afford to recognize that some agricultural 

 subjects have developed to a point in dignity 

 of effort and scholarship where they might 

 profitably be included in the curriculum be- 

 side older and more familiar academic fields. 

 The advances of the last few years in second- 

 ary rural education and in the standard of our 

 American agricultural colleges is worthy cause 

 of gratification. But it is almost a disgrace 

 that our principal universities are utterly 

 failing to train and provide leaders and teach- 

 ers for what must always be our country's 

 chief field of endeavor; and to recognize that 

 the art of agriculture is passing — rapidly pass- 

 ing in the United States — from the avocation 

 of the artisan to the profession of the highly 

 trained specialist. Dr. Russell's book will not 

 be the least of the instruments to bring about 

 the change. Frank K. Cameron 



SEABK INTOXICATION^ 



The flesh of the economically very impor- 

 tant Greenland shark (Somniosus microceph- 

 alus), a shark usually between 6 and 14 feet 

 in length occurring abundantly in the Arctic 

 Ocean and ranging southward to Norway, the 

 Faeroes, Iceland, Cape Cod, Oregon and Ja- 

 pan, has long been known to possess certain 

 poisonous qualities. 



It is not known to what extent the poison- 

 ous nature of the flesh of this fish is shared by 

 that of other species of sharks, some of which, 

 at least, appear to be quite harmless; but in 

 view of the possibility that in the near future 

 the flesh of some of our more abundant spe- 

 cies of selachians may be placed on the market 

 for the purpose of providing a cheap supply 

 of good fresh food, it would seem opportune 

 to call attention to what is known in regard to 

 the undesirable qualities of the flesh of the 

 Greenland shark in order that similar quali- 

 ties in the flesh of other species, if present, 

 may be inamediately detected. 



Mr. Ad. S. Jensen, of the zoological mu- 

 seum of the University of Copenhagen, has re- 



1 Published witt tlie permission of the secretary 

 of the Smithsonian Institution. 



