N%cn a 30 weight p¢ ferrous chloride solution is quick cooied to 78"K, it forms-a transparent glasr When this is slowly.w&ned; both differential thermal analysis and Xlijssbauer measurements distinguish four temperatures, wbidh correspond to (1) melting from glass to undercooled liquid, (2) crystallization of salt-free ice. (3) crystalliza-'r tion of FeCl~;9H~O, and (4) melting of both crystals. Our recent differential-thermal-analysis measurements show that the third temperattiIe increases bjr 22Β°K.as the fraction of DzO in the water increases from zero to 100 percent, &h&he other three remain nearly constant. The cause of the large isotspe effect is not known. .' These measurements on fro&n aqueous solutions of ferrous &loride by use of differential thermal analysis are. a supplement to our larger study of the glassy stat& of matter.by.us+ of the-h4fassbauer eff&t. This DTA technique, which is well adapted for studying phke changes in solids, consists basically in me%.uring the tetip,erature differences between a sample arid a ,matched reference cell when bsth are placed in an oven that is warmed at a steady rate. Melting and freezing L endo-and exothermic processes -are seen ',' '.