MEMOIR OP SWAMMEBDAM. 27 



by blowing them up with air, after being properly 

 evacuated and cleansed, an invention which developed 

 and stiffened the parts as effectually as an injection of 

 wax, while it did not render them opaque and confus- 

 ed, as that substance is liable to do. 



He obtained his degree as Doctor of Physic on the 

 22d February, 1667, after a public defence of his 

 thesis on Respiration. On this production he again 

 concentrated his attention, and after thoroughly re- 

 vising and enlarging it, speedily committed it to the 

 press. It was published in the March following, 

 and dedicated to his friend and patron Thevenot. 

 Like all this author's works, it is distinguished for its. 

 originality, and most of the statements made, are the 

 result of patient observation and experiment. But 

 many of its views were too much opposed to gener- 

 ally received opinions, to be readily admitted ; and 

 the occasional introduction of extraneous matter, laid 

 the work open to objection. Among other attempts 

 made to refute its doctrines, there was one by John 

 Baptist Van Lamsweerde, more remarkable for acri- 

 mony than talent, in a publication entitled, "An 

 Expiration of Swammerdam's System of Respiration." 

 But the work contained so many valuable observa- 

 tions and experiments, that it had no difficulty in 

 withstanding these desultory, though spirited attacks, 

 and ultimately took its place among those which 

 have materially contributed to advance our know- 

 ledge of animal economy. No fewer than three 

 editions have been printed at Leyden, of the re- 



