The laws of energy and momentum conservation were formulated for a jet of a
n arbitrary liquid during its capillary disintegration. These laws yield si
mple universal (independent of the jet diameter and liquid properties) equa
tions that describe the decrease in the jet velocity (the self-retardation
effect) and in its internal energy during disintegration as functions of th
e initial velocity. The Bernoulli equation for steady-state flow of an idea
l liquid was generalized for the disintegration of a real liquid jet.