nasal obstruction, such as a bad “cold in the head,” as Æsop’s fox was clever enough to remember, This type is temporary and remediable. But there are other forms that are due to nerve-disease, and for these nothing can be done.
A congenital anosmia is occasionally met with, and a curious partial anosmia, reminding us of colour-blindness or tone-deafness. I myself know people who cannot smell coal-gas unless it is very strong, and I once knew a cook,—a cook who couldn’t smell a bad egg !
Albinos are said to be congenitally anosmic, and there was recorded many years ago by Hutchison the case of a negro who, gradually losing all his pigment, became anosmic in consequence (cited by Ogle). As the sustentacular cells of the olfactory area contain granules of pigment (see Chapter II.), we are forced to conclude that it must exercise a highly important function in the perception of odours. We shall see later on that its presence is supposed by some to support the theory that odour is a specific ethereal vibration similar to light.
We turn now to discuss the real nature of odour, a section of our subject which is still theoretical and highly problematical.
Having accomplished so much in the art of perfumery, the chemist ought, one would think, to be
