Many races living in hot countries deliberately sour all the milk directly after milking, by putting sour milk into it, because, when soured, it will keep fairly wholesome for several days, while if not soured it would entirely spoil and become unusable within twenty-four hours.
"A Handbook of Health"
Woods Hutchinson
We have stated essentially that each mortal upon departing from this life enters into conditions where human language is not only not needed, but is unusable; therefore we may be asked how returning spirits can possibly speak to us in our language, which is no longer at their command.
"Witchcraft of New England Explained by Modern Spiritualism"
Allen Putnam
If you put a gummy substance inside the tube, the next flat will stick the tube to the casing and make it unusable.
"Simple Sabotage Field Manual"
Strategic Services