30 DIVERS AND HAÖA. 



that it can not ])e drained dry on the tile, or rendered dry in the 

 desiccator exce[)t at tlie surface of its masses. Yet it is not in the 

 least delit^^nescent, and becomes dry in the air when spread out in very 

 thin layers ; indeed in very dry air it is even sliglitly efflorescent. 

 Analysis shows it to contain water, hut it loses this only very slowly 

 even at 115.° Under the microscope it is seen to consist of intei-lacin<i-, 

 vei'v long, slender needles. It is only very slightly soluble in water, 

 only sufficiently so to cause the water to give a very slight opalescence 

 with sulphuric acid. It is nlknline to litmus. It is decomposed a 

 little by solutions of alkali carbonates. It may be dissolved in dilute 

 nitric acid, and, with very rapid treatment, re precipitated unchanged 

 by barium hydroxide. This is a property which, witli precautions, 

 may be taken advantage of to remove sodium sah, whicli is nearly 

 always present in the original precipitate, but always absent after 

 second precipitation. Only once did we get the original preci])itate 

 free from sodium. Analysis gave — 



Calc. Found. 



Barium 48'8,S 47-«)l 



Sulphur lo'O.S 15-04 



Nitrogen o • 2 9 o • H 1 



The calculation is for Ba.N/SC),),, (Oil.,),,. The alkalinity of the salt, 

 measured by decinormal acid and methyl orange, proved equal to one- 

 third of the bariiun. 



Ammonia added to a solution of the salt next described converts 

 it into tribarium imidosulphonate insoluble, and ammonium imidosul- 

 phonate. 



Barium htjdroijen iiiiiiloxulj)]ioiinli'. — This salt has been briefly 

 noticed by Jacquelain and by P)erglund. We have prepared it from 

 the tribarium salt, thoroughly free from scxliiim. by cautious treatment 

 with dilute sulj)huric acid equivalent to slightly less than one-third 



