Buried bottle

Why would anyone bury beneath their kitchen floor a bottle filled with oil and with its neck jammed full of pins? In 1960 Mr. and Mrs. Forster, of 39 Norfolk Street , Boston were asking this question after they found such a bottle beneath their kitchen floor. It all came about when they decided to have a new floor in their kitchen to replace the original brick one.

39, Norfolk Street, Boston.

"The bricks were laid in earth," Mrs. Forster said at the time, "then beneath the earth was a layer of ashes, and beneath that a layer of chalk, and the bottle, standing neck down, was buried in the chalk." The bottle was cylindrical and was filled with what appeared to be a light oil. In cleaning it, Mrs. Forster would appear to have broken the seal for afterwards it contained a few air bubbles and there were none when she and her husband found it, and similarly some of the pins became dislodged from the neck and fell down inside the bottle.
From the obvious care with which it was buried, it would seem that it had a serious purpose and from its position in the chalk Mrs. Forster deduced that it had been there since the house was built. Incidentally, the bottle was buried directly in front of the outer door and about a foot inside the room. Could it perhaps have been intended to prevent evil spirits or witches or similar unwelcome visitors from entering the new house, or did some other strange belief or superstition lie behind its presence there?