Short-lived, picosecond, collision-induced spontaneous Raman scattering processes in liquid water, heavy water, and aqueous solutions give rise to a totally featureless base line whose intensity, I{sub c}, decreases rapidly from {omega} = 0-6000 cm{sup {minus}1}. The well-known inter- and intramolecular vibrational scattering is separated from the collision-induced scattering by this base line; that is, the vibrational Raman scattering lies above it. The collision-induced base line for water is approximated in the Stokes spectrum, from 20 to 4500 cm{sup {minus}1} only, by the relation I{sub c} = k/{omega}{sup m}, where m, which rises slightly with temperature, equals about 1.2-1.3. However, more extensive data from 0.6 to 6000 cm{sup {minus}1}, obtained at 26{degree}C, produced the more general relation, ln I{sub c} = A exp(-B(ln (1 + {omega})){sup 2}), and Fourier transformation gives the average correlation time of the collision-induced polarization, C(t). C(t) = {integral} I{sub c} exp(i{omega}t) d{omega}. C(t) declines rapidly from unity and becomes zero just above t = 4 ps. Subtraction of the collision-induced base line in the low-frequency (< 350 cm{sup {minus}1}) region of water followed by Bose-Einstein reduction gives the intermolecular vibrational intensity, (I{sub T} - I{sub c})/(1 + n), where I{sub T} is the total scattering. Thismore » procedure, between 3 and 95{degree}C, yielded the first observation of an isosbestic point in the intermolecular vibrational spectrum, at about 128 cm{sup {minus}1}. A {Delta}H value of 2.3 {plus minus} 0.6 kcal/mol then resulted from computer analysis. The enthalpy change refers to the disruption of hydrogen bonds, for example, for a linear O-H{hor ellipsis}O hydrogen bond transforming to a weak, bifurcated hydrogen bond, in agreement with previous intramolecular vibrational {Delta}H measurements.« less