i6 



John White 



The formula deduced from the analysis is 



When heated in a melting tube the salt rapidly turns to a 

 deep lemon color, sinters at about I57°C., and melts to an amber- 

 colored liquid at i66° to i6y°C., which does not again solidify 

 unless cooled to a very low temperature. 



There were obtained from the mother liquor, by evapora- 

 tion, long slender, hair-like needles, radiating in tufts from a 

 common center. These are white, easily soluble in the 

 mother liquor on heating, and turn yellow very quickly when 

 freed from it. They correspond in appearance and properties 

 with the ammonium lead iodid described by Wells. ^ The 

 compound in both the dry and moist condition is very sensi- 

 tive to light, turning first yellow, then brownish red, and 

 finally grayish brown. The following analytical results were 

 obtained : 



0.1430 gram substance gave 0.0678 gram lead sulfate. 

 0.1611 gram substance gave 0.0766 gram lead sulfate. 

 0.1402 gram substance gave 0.15 12 gram silver iodid. 

 0.1374 gram substance gave 0.1476 gram silver iodid. 



'^Amer. Jour. Sci., XLVI, July No. (1893); Studies from the Chemical 

 Laboratory of the Sheffield Scientific School^ vol. I, 283. 



322 



