February 12, 1915] 



SCIENCE 



255 



The curves of the Alaskan stations, the Fort 

 Liscum curve in particular, display practically 

 the same variation as that observed at Are- 

 quipa. 



The more important conclusions of my re- 

 search are: 



The dust veil produced by the Krakatoa 

 eruption affected atmospheric temperature 

 very greatly. The violent volcanic eruptions 

 of 1902 as well as the Katmai eruption of 

 1912 influenced the yearly mean temperatures 

 but very slightly or not at all. 



The pleionian variations of temperature 

 have nothing in common v^ith the presence or 

 absence of volcanic dust veils. 



Henryk Aeotowski 



Hastings-on-Hudson, N. T., 

 December 8, 1914 



SPECIAL ABTICLES 

 ON THE NATURE OF ANTAGONISM 



Explanations have been suggested by Loeb 

 and others to account for the antagonistic ac- 

 tion of various substances on living proto- 

 plasm, but none of them go far enough to 

 enable us to predict what substances (includ- 

 ing both electrolytes and non-electrolytes) will 

 antagonize each other and what degree of 

 antagonism will exist between any two sub- 

 stances. 



This kind of prediction is apparently made 

 possible by a hypothesis formulated by the 

 writer, as the result of his investigations on 

 the permeability of protoplasm. The testing 

 of this hypothesis has now proceeded far 

 enough to warrant a preliminary statement of 

 its main features. 



Substances which alter the permeability of 

 protoplasm may be divided into (1) those 

 which cause an increase, but not a decrease, of 

 permeability and (2) those which can produce 

 a decrease of permeability.^ 



The hypothesis states that substances belong- 

 ing to the first class will antagonize those be- 

 longing to the second, and vice versa. In 

 order to predict which substances will antag- 



1 Substances "which cause a decrease of permea- 

 bility may, if the exposure be suificiently pro- 

 longed, cause an increase. 



onize each other it is only necessary to deter- 

 mine to which of these classes the substances 

 belong. The amount of antagonism may also 

 be predicted, at least to a considerable extent, 

 since the greater effect of the substances on 

 permeability, the greater will be their antag- 

 onistic action. This relation may be obscured 

 by secondary causes, so that the predictions 

 which it allows will not be of equal value in 

 all cases. 



To illustrate these relations we may take a 

 series of experiments on Laminaria saccharina 

 in which the effects of salts on permeability 

 were determined by electrical measurements.^ 

 In these experiments it was found that ISTaCl 

 belongs to the first class, being able to increase 

 permeability but not to decrease it, while 

 CaClj belongs to the second class, as it is able 

 to decrease permeability.^* It was found that 

 the antagonism between ISTaCl and CaCL in 

 the case of Laminaria is well marked.* These 

 facts led the writer to formulate the hypoth- 

 esis stated above. The next step was to test 

 the hypotheses by the investigation of other 

 salts. Magnesium seemed of special interest 

 for this purpose, as in most of the writer's 

 previous experiments (on other plants) it had 

 shown no antagonism to sodium, though it 

 might be expected on chemical grounds that 

 magnesium and calcium would behave alike. 

 To the surprise of the writer it turned out 

 that magnesium was able to decrease perme- 

 ability, though its effect was much inferior to 

 that of calcium. The antagonistic relations 

 for Laminaria were then investigated, and it 

 was found that MgCl^ was able to antagonize 

 NaCl, though its antagonistic action was much 

 less than that of CaCl,.^ 



This striking and unexpected result strength- 



2 The method is described in Science, N. S., 35, 

 112, 1912. 



3 The decrease is followed by an increase if the 

 exposure be sufficiently prolonged. 



* Pringsheim 's Jahrb. f. iviss. Bot., 54, 645, 

 1914. 



5 The means by which the degree of antagonis- 

 tic action are measured can not be discussed here. 

 One method has been described in the Botanical 

 Gazette, 58, 178 and 122, 1914. 



