Hearsay evidence they do not admit from a living person, but only from one who is dead; but in the case of those who are sick or absent from the country they allow evidence to be introduced, provided it be in written form, and the absent witness and the one submitting his testimony shall alike be liable to action under the same impeachment, in order that, if the absent witness acknowledges his evidence, he may be liable to action for giving false testimony, and if he does not acknowledge it, the one who submitted his testimony may be liable.