96 



ture and it forms a layer about one-quarter inch tliielv as scraped from 

 the evaporators. T was told by the owner of the salt works that not over 

 thirty or forty busliels were obtained from the evaporation of an amount 

 of sea water that would yield 5.0(10 bushels of salt; so it will be seen that 

 the substance represents a high degree of concentration as' the average per 

 cent, of common salt in sea water is only 2.G1 per cent.* and the amount 

 of "s;ilt lime"' obtained is only about 1 per cent, of that of the commo.i 

 salt. 



Ihis high degree of concentration has led me to investigate the sub- 

 stance to see if it ix>ssesses any radio-activity, as, owing to the wide dis- 

 tribution of ra<lio-active material more or less of it must find its way into 

 the ocean, and. judging from the position of radium in the periodic sys- 

 tem, the salts of radium ought to he found as sulphates among the less 

 soluble constituents of the ocean ^^•ater. 



Experiments are now under way with a view to still further concen- 

 trate the material and to lind whether it contains any trat-e of radio-active 

 material. 



Upon consulting the literature to which I have had access, I find that 

 mention is made in nearly all cases of the separation of gypsum (CaSOi, 

 2H.O) prior to the separation of common salt in the evaporation of both 

 sea water and natural brines from wells. 



I have conducted a qualitative analysis of the salt lime in the regular 

 way and find that it does consist mainly of gypsum. It has the water of 

 crystallization and gives the reactions of Ca and SO4. It gives, moreover, 

 evidence of the presence of a small amount of carbonate of calcium. I have 

 seen no mention of this last fact in the litei'ature to which I have had ac- 

 cess. In order to determine the proportion of carbonate in the mixture 

 I pulverized about 20g. in an agate mortar until it had all passed through 

 a 100-mesh sieve ; then taking a "fair sample," as in assaying, I weighed out 

 r).GG2o grams into a .Schrottcr apjia'-atus and determined the weight of CO2 

 lost, in the usual manner. 



The weight of CO. lost was .iH.'iGg, indicating a weight of .4354g of 

 CaCOs (calculated) or .G2 i»er cent. CaCO.. A second determination gave 

 .71 per cent. 



I have tested carefully for Ba and Sr. using the ordinary f(irni of 

 chemical spectroscope as well as the regular analytical tests, and have 



*New fnternalional Encyelopoedia, p. 72?. 3.5 parts solid in 100. 77.76 per rent (it 

 solid is salt. 



