54 



Hum solution, while the control solution remained absolutely clear. 

 Into both flasks a trace of a Falmella culture, with some Diatoms, was 

 now introduced. After four weeks it was found that the Diatoms had 

 multiplied to a great extent in the control solution, but not one could 

 be observed after repeated microscopical examinations in the beryllium 

 solution. The Falmella^ however, was well developed in both flasks. 

 This might seem to indicate that such a simple alga form as Falmella 

 could utilize beryllium salts in place of magnesium salts, at least when 

 it is offered in a favorable culture solution, but slight traces of mag- 

 nesia might have been furnished by the glass vessel. 



To determine the effects of beryllium on fungi an experiment was 

 made by Molisch, the culture solution used containing — 



Pec mille. 



Ammonium acetate 20. 00 



Beryllium sulphate ,40 



Monopotassium phosphate .04 



Ferrous sulphate 01 



There was no development whatever in this solution when spores of 

 FenicilUum were inoculated, but upon the addition of 0.02 per cent 

 magnesium sulphate 78 milligrams of fungous mass was produced after 

 nineteen days. 



Notwithstanding the close chemical relations between beryllium 

 and magnesium there must exist such chemical differences that the 

 inability of beryllium to physiologically replace iriagnesium can be 

 easily explained. As the text-books on chemistry fail to give minute 

 comparisons of the chemical behavior of soluble ])eryllium and mag- 

 nesium salts toward phosphates, the writer has made a few tests in 

 this regard. When 1 per mille solutions of berylhum sulphate and 

 dipotassium phosphate are mixed the liquid is at first clear at the 

 ordinary temperature, but gradually becomes opalescent, and after one 

 day the beryllium is precipitated as a flocculent phosphate, but if the 

 mixture is heated or if some sodium acetate is added a flocculent pre- 

 cipitate is produced at once. Magnesium sulphate behaves very differ- 

 ently, giving no precipitate whatever under the same conditions. 



If a 10 x^er cent solution of monopotassium phosphate is mixed with 

 a 10 per cent solution of magnesium sulphate no precipitate is formed 

 at the ordinary temperature, and the liquid remains clear even on boil- 

 ing. This, however, is not the case with beryllium sulphate, which pro- 

 duces a copious flocculent precipitate in a few minutes, and even if more 

 dilute solutions, as for example a I per cent sohition of monopotassium 

 phosphate and beryllium sulphate, are mixed the mixture becomes 

 turbid on boiling. 



Although a higher diluted solution of beryllium sulphate gives no 

 precipitate with monopotassium i)hosphate, the addition of sodium 

 acetate, even at the ordinary temperature, will cause a precipitate of 

 beryllium phosphate. Thus even in a dilution of 0.001 i^er cent beryl- 



