Linen dusters have pockets at the sides, even those worn by women.
A small bottle of chloroform purchased at a drug store and intended for immediate use would be taken from the paper in which it was originally wrapped, and deposited handily, where the possessor could get at it with the least possible delay and trouble.
Hence, in one of those side pockets already mentioned into which the hand could be casually dropped at any instant.
The paper wrappings having been removed, the bottle would be exposed unless some other wrapper for it were improvised. The likeliest thing for that purpose, the one least likely to attract attention or comment, would be a handkerchief.
The woman, seated upon the chair at the moment for using the contents of the bottle, would remove, or partly remove, the handkerchief in which it was wrapped, and would do it with the one hand that was in that pocket with the bottle, before she rose from the chair.
What more natural than that the handkerchief should be dropped in that manner, just at the point where it had been dropped—and just an instant before the woman rose from her chair to pass around to the side of the chair in which Lynne had been seated?
Now the next point.
The rubber stopper was picked up by Patsy twenty feet away from that chair—from either of them.
The woman would not have thrown it from her at that time; such an act was not necessary. If she had merely dropped it, five or six feet would have been the extent of the distance it might have rolled away across the floor on the soft rug.
The position of the two chairs was such that in approaching the one upon which Lynne was seated at the time, the woman would have been stationed exactly between Lynne and the spot where the rubber stopper was found twenty feet away; and so, if it had been knocked from her hand in a struggle with the man to whom she was going to administer the drug, it was next to impossible that it should have rolled to the spot where Patsy picked it up.