How have courts interpreted the principle of Jarman on Wills in the context of a will?

In Whyte v. Pollok (1882) H.L. (Sc.) 400 Lord Selborne adopted the following principle from Jarman on Wills, quoting from the third edition: “The law has not made it requisite to the validity of a will that it should assume any particular form, or be couched in language technically appropriate to its testamentary character. It is sufficient that the instrument, however irregular in form or inartificial in expression, discloses the intention of the maker respecting the posthumous destination of his property; and if this appear to be the nature of its contents, any contrary title or designation which he may have given to it will be disregarded.”