It was the contents of this appended letter which had inspired Innes's remarks. Indeed, it contained matter which triumphantly established Paul Harley's theory that Sir Charles Abingdon had not died from natural causes. The letter was as follows:
No. Harley Street
My dear Merton:
I am indebted to you and to Mr. Harley for an opportunity of examining the serviette, which I return herewith. I agree that the oil does not respond to ordinary tests, nor is any smell perceptible. But you have noticed in your microscopic examination of the stains that there is a peculiar crystalline formation upon the surface. You state that this is quite unfamiliar to you, which is not at all strange, since outside of the Himalayan districts of Northwest India I have never met with it myself.
Respecting the character of the oil employed, however, I am in no doubt, and I actually possess a dried specimen of the flower from which it is expressed. This is poetically known among the Mangars, one of the fighting tribes of Nepal, as the Bloom or Orchid of Sleep.
It is found upon the lower Himalayan slopes, and bears a close resemblance to the white odontoglossum of commerce, except that the flower is much smaller. Its perfume attracts insects and sometimes small animals and reptiles, although inhalation seems to induce instant death. It may be detected in its natural state by the presence of hundreds of dead flies and insects upon the ground surrounding the plant. It is especially fatal to nocturnal insects, its perfume being stronger at night.
Preparation of the oil is an art peculiar to members
