8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 56 



volcanoes and thousands of solfataras the total output must be very large. 

 Cold chloride springs are not uncommon and are widely distributed at 

 points far distant from volcanic centers. 



Thus the question arises whether it is absurd to suppose that the 

 chlorine product of volcanoes and solfataras is sufficient to saturate the 

 unchloridized river sodium. It may be fanciful to subject such an hypo- 

 thesis to computation, but this seems to me the only way to judge whether 

 or not an absurdity is involved. Suppose then that all the chlorine were 

 emitted as chlorhydric acid. The unchloridized river sodium being taken 

 at 62.57 X 10*' metric tons each year would require very nearly 100 X 10" 

 tons chlorhydric acid. If this amount of gas were to issue from a single 

 vent, at a temperature of 300° and a corresponding pressure of 6.62 kilo- 

 grams per square centimeter into atmosphere at 0°, the opening would 

 emit 29 X lO*' metric tons per square meter per annum.' Thus the area 

 of the vent required would be 100/29 or less than 3^ square meters, so 

 that (neglecting friction) 1000 vents each of 6-J cm. diameter working 

 continuously would emit it all." Considering the many violent eruptions 

 of volcanoes and the large number of solfataras, a chlorhydric acid pro- 

 duction of 100 million tons does not seem at all impossible. If the entire 

 amount were unifonnly distributed over the globe and reached the sur- 

 face in a rainfall of one meter, this precipitation would contain less than 

 a fifth of a millionth part of chlorine. Such an amount of chlorine would 

 be recorded by hydrologists as " a trace." 



Since the only known sources of chlorine are volcanoes and juvenile 

 waters and these sources of supply are not manifestly insufficient, I con- 

 sider it fair to conclude that the juvenile chlorine is and has been since 

 the Cambrian about equivalent to the sodium set free from the rocks. 

 Doubtless there have been variations in the relations between these tM^o 

 elements which were considerable from the point of view of the hydrolo- 

 gist, but they were, apparently, not great enough to unfit the ocean for 

 the abode of a salt water fauna," or to characterize its geochemical 

 behavior. 



What the conditions were which prevailed before the Cambrian is 

 naturally more uncertain, but I do not believe that a primitive acid 

 ocean should be invoked until probable explanations involving juvenile 

 chlorine have been exhausted. If the earth is an aggregate of meteorites, 

 many of them siderolites, charged, as Mr. Clarke has suggested, with 

 lawrencite, it seems to me natural to suppose that most of this chloride, 

 whose density is nearly 3, would be deeply buried beneath the lighter 



1 Cf. Ch. Briot, Theorie Mfc. de la Chaleur, 2d ed., 18S3, Section 113. 



2 The present pig-iron production is about 60 million long tons and the weight of air which must 

 be blown into the blast furnaces proilucing this amount of pig is about 320 million long tons. 



2 Possibly fluctuations in the composition of sea-water may have affected the rate of evolution of 

 organisms or limited their survival. 



