Note 581 — PHARMACOLOGIA. (continued 5)

For such reasons there are but few wholesale houses who profess to distil it. I have, however, through the civility and attention of Mr. Johnson, chemist in Oxford-street, who frequently conducts the process on a large scale, had several opportunities of witnessing the interesting phenomena to which it gives rise. So powerful is the odour developed upon these occasions that it fills the premises with an almost insupportable atmosphere, occasioning head-ache, sickness and cough; so that we may safely observe, that, whatever miracles the prussic acid may perform, when applied to the coats of the stomach, its application in the form of vapour to the lungs proves highly irritating to those organs.

The concentrated vapour of this essential oil is almost instantly destructive to animal life. I have seen flies drop lifeless to the floor as they have passed over the still; thus, as it were, realizing in miniature the fabled powers of Avernus.

“Quam super haud ullæ poterant impune volantes

Tendere iter pennis: talis sese halitus atris

Faucibus effundens supera ad convexa ferebat.”

Æn. VI. v. 239.