98 ANIMAL EXPERIMENTATION 



from chemical stimulation, \vhen the drying of the wound 

 alters the chemical composition of the liquids which sur- 

 round the nerves. In physiological experiments there can 

 be no pressure because the wound is open, and chemical 

 stimulation by drying is prevented by moistening the cut 

 surface either with the natural liquids of the tissues or 

 with artificial solutions the composition of which accords 

 as closely as may be with that of the natural liquids. In- 

 deed, these investigations could not be made if the animal 

 suffered. The suffering would alter the blood-pressure 

 and other functions and thus destroy the value of the 

 experiment. Moreover the animal would struggle and the 

 sensitive recording apparatus could not be used. Strug- 

 gling, however, is not in itself a trustworthy indication of 

 suffering. The fowl whose head has been cut off feels no 

 pain; it is dead, but its muscles remain for a time alive, 

 and dash the body about the barnyard until the lack of 

 oxygenated blood ceases to stimulate the motor nerves. 

 Patients to whom ether or chloroform is administered may 

 struggle long after consciousness is lost. A safer guide 

 than struggling is the effect which pain has upon the 

 respiration and the circulation. The stimulation of any 

 sensory nerve will affect these functions, and no consider- 

 able degree of suffering can be present without causing a 

 noticeable change in the heart-beat and the breathing. 



We read in the newspapers that discoveries are largely 

 matters of accident. The popular opinion is that the 

 physiologist gropes about in the viscera of a living animal 

 in the hope of stumbling upon some fact which may make 

 him famous. Nothing could be farther from the truth. 

 Research is a systematic, well-ordered business, with defi- 

 nite rules of procedure. A man who applies to us for a 

 research expects: first, a problem so framed that its an- 

 swer will be a new truth; second, a method by which the 

 problem may be successfully attacked; third, assistance in 



