THE HOT HALOS OF SPIRAL GALAXIES CONTAIN MATERIAL ACCRETED FROM THE INTERGALACTIC MEDIUM AND MATERIAL EXPELLED FROM THE DISK. THE MASS IN EACH COMPONENT CONSTRAINS GALAXY FORMATION MODELS AND CAN BE DISTINGUISHED BY THE RNETALLICITY. HOWEVER ISOLATING THE HOT GAS AND MEASURING ITS METALLICITY REQUIRES A LARGE NUMBER OF PHOTONS AND HALOS TEND TO BE FAINT. THE BEST CANDIDATE IS NGC 891 A NEARBY EDGE-ON MILKY WAY ANALOG WITH AN X-RAY BRIGHT HALO. EXISTING DATA INDICATE AN ACCRETION RATE OF 0.2 MSUN/YEAR BUT THERE ARE TOO FEW PHOTONS TO RULE OUT SEVERAL OTHER PLAUSIBLE HALO MODELS. WE WILL MEASURE THE ACCRETION RATE AND THE HOT GAS COMPOSITION UP TO 8 KPC FROM THE DISK.