During the past two years the writers hare studied a series of some forty alloys of gallium and indium covering the entire range of composition from pure gallium to pure indium. Search of the literature reveals no previous study of such alloys, this lack of study being due, no doubt, to the prerious scarcity of the two metals.In 1936 a progress report2 was presented covering the determination of the eutectic in the system gallium-indium. The present paper includes that work (which was not published) and completes the study of this alloy system. EXPERIMENTALBecause of the relatively high cost of the metals involved it was essential to work with small amounts and to develop a technique suitable to such work. In the customary methods for studying alloy systems amounts up to 15 or 20 g. are used and time-temperature curves are plotted. The eutertic alloy may be squeezed out and analyzed.In place of the usual time-temperature curve, the writers used temperature-temperature curves in which the temperature of the alloy was plotted against the temperature of its bath. This method is, of course, possible only where the alloys concerned have low melting points. Time was kept as nearly constant as possible in all determinations, the rate of temperature change being approximately one degree per minute.An iron-constantan thermocouple prepared of fine wire and coated with high-grade white shellac was used for determining the temperature of the alloy. During the work on the gallium side of the curve the alloy was used as the variable cold junction, the hot junction being placed in a constant-temperature bath of boiling water. The hot junction assembly was specially prepared and consisted of a Kjeldahl flask, to one side of the Present address:

Notes 689 1,2,3 ,4-Tetrahydrodibbnzofuran DerivativesM. p" °C, Analyses, % Substance (corr.) Formula Caled. Found 7--Bromoacetyl-81-82 CuHisOjBr Br, 27.27 27.72 7-l2-(Dimethylamino)-l-oxo-ethyl]-hydrochloride 244-247 CuHaANCl Cl, 12.07 12.06 N, 4.77 4.73 7-[2-( Diethylamino)-1 -oxo-ethyl ¡-hydrochloride 202-210 CiiH2402NCl Cl, 11.03 11.11 N, 4.35 4.19 7-[2-Piperidino)-l-oxo-ethyl]-hydrochloride 235-239 Ci,HmOjNC1 Cl, 10.63 10.65 N, 4.20 4.59 7-[2-( 1,2,3,4-Tetrahydroisoquinolino)-l-oxo-ethyl ¡-hydrochloride 260-264 c23h24o2nci N, 3.67 3.64 7-[2-(Dimethylamino)-l-hydroxy-ethyl ¡-hydrochloride 220-222 c,6h22o2nci c, 64.95 65.40 H,