We present echelle spectroscopy in the 3500 to 10300AA range of the Hourglass Nebula which is embedded in the galactic HII region M8. The data were obtained using the 2.1 m telescope at Observatorio Astronomico Nacional in San Pedro Martir, Baja California. We have measured the intensities of 274 emission lines, in particular 88 permitted lines of C+, N0, N+, O0, O+, Ne0, S0, S+, Si0, Si+ and Si++, some of them produced by recombination only and others mainly by fluorescence. We have determined electron temperatures and densities using different line intensity ratios. We derive the He^+, C++, O+ and O++ ionic abundances as well as --for the first time in a nebular object-- the total O abundance from recombination lines, these nebular values are independent of the temperature structure of the nebula. We have derived also abundances from collisionally excited lines for a large number of ions and elements, these abundances do depend on the temperature structure. Accurate t^2 values have been derived by comparing the C++, O+ and O++ ionic abundances obtained making use of both, collisionally excited lines and recombination lines. A comparison of the solar, Orion nebula and M8 chemical abundances is made.