Introduction I n the study of the hydrides of germaniiiiii. Dennis, C'orey and Moore? used an apparatus n-liich was a modified foriii of that employed by Stock3 in hie work on the hydrides of horon and silicon. Thi9 apparatus has heen rniployed in subsequent inyestigation$ in this lahorntory in the course of which it has undergone consiclerahle iiiodification. T o simplify the discussion of experimental details in the several articles Inter to he published, the most recent foriii of this apparatus is here tlescrihetl antl the new features of manipulation are discussetl. The main chain of apparatus as shown in Fig. I differs from that clescbrihed hy Dennis, Core!- 2nd lloore in the follon-ing essential features. Stock's iiiodification-' of his niercur?- float mlve is eniploj-et1 and has 1 : e m foiintl to lie T-ery satisfactory, The fractionation l~ulhs,R1. R2. and Rs.are attaclietl to the innin line In the apparatus as !rethrough mercury floating valves I-?.I-:
