June 9, 1911] 



SCIENCE 



895 



and moon it in turn attracts both earth and 

 moon. The tendency for the earth and moon 

 to approach each other is greater than before 

 the pound mass was raised from the surface 

 of the earth; the potential energy of the sys- 

 tem is increased by an amount equal to the 

 energy expended in raising it and there is no 

 more a disappearance of energy to be ac- 

 counted for than in the simpler case where a 

 mass subject to no attraction but the earth's 

 is raised above the earth. 



E. S. Hanson, Jr. 

 Columbus, Ohio, 

 April 29, 1911 



V 



SCIENTIFIC BOOKS 



(Edema. A Study of the Physiology and 

 Pathology of Water Absorption hy the Liv- 

 ing Organism. By Martin Fischer, M.D. 

 Pp. 209. New York, John Wiley and Sons. 

 1910. 



A trenchant alternative to current and gen- 

 erally accepted ideas of the distribution of 

 water in the organism is presented by Fischer 

 in this essay. The familiar reference to fil- 

 tration, diffusion and osmosis as explanatory 

 factors is notably absent and, instead, the 

 part played by the colloids in the cells and 

 body fluids is emphasized. That some col- 

 loids, such as gelatine, for example, are able 

 to take up water and thus enormously to in- 

 crease their volume is common experience. 

 Such " hydrophilie " colloids Fischer has in- 

 vestigated with reference to the conditions 

 which cause them to take in water or to give 

 it forth. The degree of swelling of the col- 

 loid depends on its nature and also on the 

 character of the solution in which it is placed. 

 Thus both gelatine and fibrin swell more in 

 alkaline or acid solutions than in water, both 

 have the amount of swelling in acid or alka- 

 line solutions reduced by the presence of 

 electrolytes, and in both the addition of non- 

 electrolytes fails to exert the checking effect 

 produced by electrolytes. By extensive experi- 

 ments Fischer has demonstrated that the 

 body tissues, represented by muscle and the 

 eyes, when immersed in water, or in acid and 

 alkaline solutions, or in combinations of acid 



and alkaline solutions with various electro- 

 lytes, behave in a manner quite analogous to 

 gelatine and fibrin. 



On the basis of these experiments the sug- 

 gestion is offered that cedema is induced when- 

 ever, in the presence of an adequate supply of 

 water, the affinity of the colloids of the tissues 

 for water is increased above what we call 

 normal. Particularly by the accumulation of 

 acids in the tissues is the afiinity for water 

 increased. Thereupon Fischer proceeds to 

 show that states in which oedema develops are 

 accompanied by an abnormal production of 

 acid, that under such circumstances oedema 

 can be reduced by the same agencies (electro- 

 lytes) which decrease the affinity of hydro- 

 philie colloids for water, but remains unaf- 

 fected by non-electrolytes, and that experi- 

 mental production of acids in tissues results 

 in the development of oedema. 



The argument thus devised for the explana- 

 tion of oedema in general is applied to the 

 peculiar phenomena of oedema in special or- 

 gans, and is then extended to other biological 

 phenomena in which the transfer of water 

 plays an important role, as in haemolysis, 

 growth and urinary secretion. 



The experimental procedures on which the 

 conception described in this volume is 

 founded are of the utmost simplicity, and can 

 be readily tested by any one. Fischer's appli- 

 cation of these simple tests to conditions in 

 the body is made with much ingenuity and 

 in many instances with compelling convic- 

 tion. To what extent the process can be used 

 to explain certain results of experimental pro- 

 cedures which cause increased production of 

 lymph, or which vary the amount of urine 

 secretion, remains to be seen. Certainly the 

 conception is highly suggestive, and well 

 worth putting to further test. 



The subject is expounded by Fischer with 

 clearness, with enthusiasm, and with evident 

 assurance of the adequacy of the theory to 

 meet the demands that can be put upon it. 

 The essay was awarded the Nathan Lewis 

 Hatfield Prize by the College of Physicians 

 of Philadelphia in 1909. 



W. B. Cannon 



