MEMOIR OF SWAMMERDAM. 
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 
2 2d February, 16'67> 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- 
