vm] in the Eighteenth Century. 203 



sciences to the elucidation of physiological phenomena ; and 

 the width and sagacity of his teaching are reflected in the work 

 of his great pupil who followed after him, Albrecht von Haller, 

 of whom I have soon to speak. 



Boerhaave cannot be said to have made by his own researches 

 any striking contribution to our knowledge of digestion. The 

 part which he played was rather that of the sagacious eclectic 

 teacher who has made himself well acquainted with all that 

 others have done, and who criticising, with wide knowledge, 

 their various views, and pointing out where they are obviously 

 wrong, gathers together what might seem to a sober mind the 

 outcome of their various results. 



Thus Boerhaave was not an extreme advocate either of the 

 mechanical school or of the chemical fermentative school, but 

 he admitted within limits the doctrines of each. 



In his works, as for instance in his Institutiones Mediae 

 (the first edition of which appeared in 1708), which remained 

 for many years the common text-book of the schools, and the 

 first part of which was a treatise on physiology, he recognizes 

 that digestion is in part a solution of some of the constituents of 

 the food by means of various juices. Saliva, the juice from the 

 oesophagus, the gastric fluid, which consists in part of a viscous 

 secretion, poured out by the glands of the stomach, and in part 

 of a thin fluid secreted by the arteries, the bile, the pancreatic 

 juice, and the intestinal juice, each of these contributes to the 

 result. But he regards the solution effected by means of these 

 juices as of the nature of ordinary solution, not of a nature of 

 fermentation. It is worth noticing that he denies the acidity 

 of the gastric juice, and speaks of van Helmont's heresy 

 on this point. Owing to the labours of Sylvius, Stahl, and 

 others, men's ideas concerning acidity and alkalinity were 

 becoming much more definite than they had been ; coloured 

 vegetable juices were coming into use as tests of one or the 

 other ; and Boerhaave, while denying the acidity of gastric 

 juice, expresses his wonder that Sylvius, knowing as he did 

 what an acid was, could ever have thought that pancreatic 

 juice was acid. It may be added that Boerhaave regarding, in 

 common with his contemporaries, the supply of nerves to the 



