460 BIOLOGICAL PHYSICS 



rhythmic succession and gradually declining intensity until 

 the condition of rest is ultimately regained. 



So rhythmic and continued is the act sometimes, that 

 a see-saw feeling is experienced throughout the body for 

 a period of time, very much akin to what the unseasoned 

 sailor is familiar with on regaining terra firma after a 

 voyage on the " briny deep." 



Who then can doubt the importance of this act, or 

 series of actions, in the economy of a complex organism 

 like a living vertebrate animal ? 



It slows the pulse considerably, lessens the number of 

 the respirations, and is succeeded by a feeling of oscillatory 

 movement, which lasts for some seconds, or until the 

 function of respiration is fully resumed. 



The muscular system is thus like a stringed instrument, 

 " attuned " to the proper performance of its duties, the 

 motor and sensory nerve trunks are straightened out, 

 so that nerve impulses can travel to and fro without 

 interruption, the slow and unapparent lymphatics receive 

 a stimulus, mechanical and vital, which expedites their 

 circulation, while the interstitial cellular tissues are, more 

 or less, unloaded of their passive contents, and the blood 

 circulation, although slower,* strengthened and steadied. 

 Moreover, it further seems to us, that the whole liquid 

 contents of the nerve structures sustain a push, by which 

 their position is, more or less, changed within their 

 enclosing sheaths, and their regular distribution improved 

 or more completely obtained. 



"Sneezing" 1 is one of the same class of acts as 



1 On June 29th, 1899, we wr te to the Editor of the British Medical 

 Journal, as follows : Dear Sir, A medical friend of mine, who is 

 acquainted with some work I have done during the last twenty years 

 in certain departments of neurology, has drawn my attention to a 

 "Literary Note" which appeared on page 1552 of your issue of the 

 24th inst., and which reads as follows : " A work by Dr. St. Clair 

 Thomson entitled ' The Cerebro-Spinal Fluid, its Spontaneous Escape 

 from the Nose,' is in the Press. The book will be published by Messrs. 

 Cassell & Co." 



Before the publication of the work above referred to becomes, or is 

 accomplished, my friend thinks, and I agree with him, that it is necessary 

 for me to ask you to be good enough, to allow to appear in your earliest 

 available issue the following extract from a paper entitled : " On the 

 Physiological Nature and Import of the Actions of Yawning, Stretching, 



