ANALYSIS OF CERTAIN SMOOTH MUSCLE 
RESPONSES 
B. M. HARRISON AND FRANCIS M. BALDWIN 
The fact that smooth muscles differ fundamentally in their 
structure from the cross-striated form, and that they possess dis- 
tinctive physiological properties, especially in their toxicity, rhythm 
and rate of response, has made them the object of rather ex- 
tended investigations. It is not necessary here to review ex- 
tensively the literature dealing with the various points of attack 
contributory to an understanding of the responses of such ele- 
ments. Budington^ in his paper on annelid muscles brings to- 
gether an extended bibliography summarizing the work in this 
field prior to 1902, especially that done on muscles of the inverte- 
brates. Inasmuch as his work was with the muscles of the body 
wall of the earthworm which is one type concerned in the present 
paper, reference to his results will be made later. Subsequently 
such workers as Bethe^ (1903), Griitzner^ (1904), von UexkiilP 
(1905-1908), Meigs^ (1908, 1909, 1912), Snyder® (1914), SatanP 
(1919) and many others have contributed much to our knowledge 
of smooth muscle responses, from both the theoretical and the 
practical sides. The present paper is a preliminary report of an 
attempt to analyze the responses of smooth muscles when sub- 
jected to different conditions, and especially when immersed in 
solutions of computed strengths of the alcohols, and continues in 
a comparative way a study reported recently by one of us (Bald- 
win®) using the voluntary gastrocnemius muscle of the frog. 
APPARATUS AND METHOD 
The apparatus used was adapted from that described in former 
experiments® and differed chiefly in an adjustable modified light 
muscle lever mounted in such a way as to subtend the muscle 
within the glass chamber into which fluids could be easily intro- 
duced and removed.* As a check on time of stimulation and dur- 
* The muscle lever used in these experiments was made of very thin aluminum 
sheet, 31 cms. long and mounted upon very delicate knife blades as a fulcrum. Deli- 
cate knife blades also were mounted at the point of attachment of the muscle and the 
ratio was so computed that an approximal balance was effected. The ratio of magnifi- 
cation was 1:30, and the mechanical impediments were reduced to a minimum. The 
