•22i PROCEEDINGS OF THE AMERICAN ACADEMY. 



Action of FebbOUS Iodide with Ammonia. 



When anhydrous ferrous iodide was exposed to a stream of ammonia 

 gas at any temperature between and 100 , a large amount of the gas 

 was absorbed^ and the iodide was converted into ;i voluminous white pow- 

 der. The composition of this substance was determined by finding the 

 increase in weight during the treatment with ammonia. 



I. 8.5507 grams of ferrous iodide gaiued 1.1701 grams of ammonia. 

 II. 2.0-111 grams gained 0.844 ( J gram of ammonia. 



The substance therefore corresponds in formula to the compound FeCl s - 

 6NII 3 made from ferrous chloride under the same conditions. 



Properties of the Hexammonia Fi rkoi s Iodide. 



It forms a pure white amorphous powder, which occupies many times 

 the volume of the ferrous iodide from which it is made, ami has a very 

 low specific gravity. "Water decomposes it at once with a considerable 

 rise of temperature; the products are ferrous hydrate, amnionic iodide, 

 and ammonia. We did not succeed in finding an organic solvent for 

 it. When exposed to the air it gives off ammonia rapidly and turns 

 brown; in an atmosphere of ammonia it remains unaltered even at 100°; 

 heated in an indifferent gas it loses ammonia, and is converted into a dark 

 brown powder, which seems to be stable in the air. Two analyses indi- 

 cated that this brown substance contained between two ami three mole- 

 cules of ammonia to each molecule of ferrous iodide. Its stability in air 

 leads us to think that it is a new compound, but evidently it was not pure. 

 as the analyses differed by three per cent. Unfortunately we could find 

 no way of purifying it. 



Action of Bromine on Hexammonia Ferrous Iodide. 



When the compound FeI/>XII , was exposed to the vapor of bromine, it 

 absorbed a large quantity, so that the product in one case contained 71.03 

 and in another 70.41 per cent of bromine. This apparent constancy in 

 the amount of bromine absorbed led us to examine the product more care- 

 fully iu the hope that it might be a definite compound, but onr exper- 

 iments have convinced us that it is only a mixture essentially made up 

 of ferric bromide, ammonic bromide, and an amnionic bromiodobromide 



