1887.] Prof. J. B. Haycraft on the Sense of Smell . 
215 
Professor Ramsay examined several of these groups, and came to 
the following conclusions : — In the first case, that the smell of a 
group was generic ; and, in the second case, that the smell became 
more distinct, and gained in flavour in ascending from the lower to 
the higher members. My observations are not quite in accordance 
with the first statement, for I do not believe any uninitiated person 
would find any resemblance, say, 1 between the odours of ethyl 
alcohol and octyl alcohol, or of acetic and valeric acids, which 
would prompt him in any way to class them together. I find that 
in ascending the organic series, as in ascending one of Mendelejeffs 
groups, the odour changes. This change may be slight, so that it 
may be said with truth that there is a generic smell belonging to 
the series ; or, more frequently, the change is so great that it is only 
by a study of intermediate members that any continuity of sensation 
can be made out. 
These statements may be verified by a study of the following 
tables. They are not as complete as I could have wished, owing to 
my inability to obtain some of the rarer acids and alcohols. 
Monatomic Alcohols. 
CH 3 .OH Methyl alcohol = 
C 2 H 5 .OH Ethyl „ = 
C 3 H 7 .OH Propyl „ = 
C 4 H 9 .OH Isobutyl ,, = 
C 5 H u .OH Amyl 
C s H l7 .OH Octyl „ = 
Faint alcoholic odour. 
Alcoholic odour. 
Alcoholic odour with flavour. 
[ Flavour becomes more marked, and 
the alcoholic odour less and less. 
The term “ flavour ” expresses very badly what is meant. It is 
only possible by experiment to become acquainted with the nature 
of a smell. 
Among the fatty acids another flavour equally characteristic 
gradually supersedes the acetic odour of the first two members 
of the group. 
CHO.OH Formic acid 
C 2 H 2 O.OH Acetic ,, 
C 3 H 5 O.OH Propionic ,, 
Fatty Acids. 
= Acetic odour. 
= Acetic odour. 
= Acetic, together with a flavour. 
