provision that the proviso makes and its
real effect cannot be put out of consider-
ation in determining where the burden of
proof lies. When an enactment is stating
the grounds of some liability that it is
imposing cr the conditions giving rise to
some right that it ius creating, it is
possible that in defining the elements
forming the title to the right or the basis
of liability the provision may rely upon
qualifications exceptions or provisos and it
may employ negative as, well as positive
expressions. Yet it may be sufficiently
clear that the whole amounts to a statement
of the complete factual situation which must
be found to exist before anybody obtains a
right or incurs a liability under the
provision. In other words it may embody the
principle which the legislature seeks to
apply generally. On the other hand it may
be the purpose of the enactment to lay down
some principle of liability which it means
to apply generally and then to provide for
some special grounds of excuse, justific~
ation or exculpation depending upon new or
additional facts. In the same way where
conditions of general application giving
rise to a right are laid down, additional
facts of a'special nature may be made a
ground for defeating or excluding the right.
For such a purpose the use of a, proviso 1s
natural. But in whatever form ttle enactment
is cast, 1f it expresses an exculpation,
justification, excuse, ground of defeasance
or exclusion which assumes the existence of
the general or primary grounds from which
the liability or right arises but denies the
right or liability in a particular case by
reason of additional or special facts, then
it is evident that such an enactment
supplies considerations of substance for
placing the burden of proof on the party
seeking to rely upon the additional or
special matter: see Morgan v. Babcock &
Wilcox Ltd. (1929) 43 C.L.R. 163; Pye v.
Metropolitan Coal Co. Ltd. (1934) 50 C.L.R.
614, (1936) 55 C.L.R. 138; Darling Island
Stevedoring & Lighterage Co. Ltd. Vv.
Jacobsen (1945) 70 C.L.R. 635; Barritt v
Baker (1948) V.L.R. 491, at p. 495; Dowling
v. Bowie (1952) 86 C.L.R. 136."