172 
IOWA ACADEMY OF SCIENCE Vol. XXVIII, 1921 
alcohol than any other concentrations of its predecessors (see 
Figs. 3, 4 and 5 in comparison). 
Hexyl and Heptyl alcohols. — No hexyl alcohol was available 
at the time of experimentation so that no records were obtained. 
Heptyl alcohol was at hand and its effects on fatigue in different 
concentrations were explored somewhat but due to incomplete- 
ness of records no comparisons of value can at this time be 
made. 
Octyl alcohol. — Two isomeric solutions of this alcohol were 
tried, a secondary octyl from a purification process of the East- 
man Kodak Company, and a so-called capryl alcohol from the 
same source, redistilled here. Little difference physiologically 
could be seen in using either in similar saturated solutions. Both 
give curves (Figs. 28 and 29) in strong and saturated solutions 
which are remarkable in their similarity, not to their immediate 
predecessors of equal strengths, but to ethyl alcohol. The three 
lower concentrations, however, give curves (Figs. 30, 31 and 32) 
which are fairly comparable to similar concentrations of butyl 
alcohol, with perhaps a less marked similarity to the weakest 
strength of ethyl and propyl alcohols. These considerations when 
taken together with certain other data seem to point to the fact 
that octyl alcohol in various concentrations does not have as strik- 
ing penetrating qualities as butyl, propyl or amyl alcohols. From 
incomplete records obtained in use of heptyl it would seem that 
this alcohol also is in a similar category. 
SUMMARY 
By making use of a proper laboratory apparatus herein de- 
scribed in which experimental conditions may be kept reasonably 
constant, records were obtained in the development of fatigue in 
the gastrochnemius muscle of the frog while it was being sub- 
jected during its stimulation to certain computed concentrations 
of various alcohols. 
The ranges of concentration explored may be briefly tabulated ; 
strong and saturated solutions of methyl, ethyl, propyl, butyl, 
amyl, heptyl, octyl and capryl, with computed graduations in three 
series of each, varying from 29.1 methyl, to 0.62 vol. per cent 
octyl ;• 20.8 vol. per cent methyl, to 0.29 vol. per cent octyl ; and 
12.4 methyl to 0.15 vol. per cent octyl, respectively. 
On comparative analysis of the various phases of these curves 
certain inferences can be drawn as to penetration of the different 
alcoholic concentrations used and their resulting effects on the 
