vv The LIFE of JOHN SWAMMERDAM. 
himfelf greatly in anatomy, by making the proper ufe of fo favourable an 
opportunity. fo 
But this was not the only opportunity which providence threw in our 
author’s way at this time, as the principal phyficians of Amfterdam had 
formed a college, and had agreed to meet together every other week in 
order to confer on medical, but chiefly anatomical fubjeéts, and to make 
experiments relative thereto. The obfervations of this fociety of learned 
men were afterwards publifhed by Cafper Commelin, in the year mpcixvi and 
Lxvil, before Swammerdam had been created doétor of phyfic ; notwith- 
ftanding which, he was the firft to furnifh materials for it. It was he, and 
he alone, that made in the faid college, with his own hand, a drawing of 
the fpinal marrow, publifhed by Blafius at the fame place; and on this 
occafion he wrote to Thevenot the following particulars. I. That the 
{pinal marrow confifts entirely of fibres. JI. That thofe diftin@ fibres meet 
and terminate in fome part of the brain. JI. That there iffue fibrous nerves 
from the fibres of the fpinal marrow. IV. That the pia mater is altogether 
extended into hollow fheaths. V. That all thefe things may be eafily feen, 
by fuddenly placing the yet warm fpinal marrow along with the vertebrae 
containing it, in cold water, and breaking the vertebre with great caution 
from the marrow, after having fuffered both to remain in that fituation during 
the fpace of a day anda night. ‘This letter was written the firft of April 
MDCLXv1; our author at the fame time tried many experiments by injecting the 
veffels of living animals with various liquids. See de Refp. page 103 and 107. 
He even made fome chemical experiments on the cold fermentation produced 
by mixing together the falt of urine, and the fpirit of glauber falts, ibid. p. 111. 
He then too compofed that laborious effay on refpiration, which he was to 
maintain on his declaiming for his degrees in phyfic. We may be convinced by 
reading this performance, that he only purfued fuch things as he thought of 
in his own way, and of whofe truth he had fatisfied himfelf, and could con- 
vince others by experiments, without borrowing any afliftance from other 
writers. Having finifhed this differtation, he came back to Leyden to take 
out his degrees; and took occafion of his ftay there to cultivate a moft 
intimate friendfhip with the famous Van Horne, who had been formerly his 
preceptor in the ftudy of anatomy. With this gentleman he then practifed 
this ufeful art, and prepared a great many things in many various ways, 
while both publickly owned a community of fentiments and difcoveries. 
The profeffor moft liberally fupplied all kinds of materials, the other directed 
the work, and at the fame time made with his own hands the moft mafterly 
drawings of each difcovery, which he immediately forwarded with fuitable 
obfervations to Matthew Slade. Nothing here was wanting to carry on fo 
laudable an undertaking. Van Horne’s liberality contributed the fubjects, the 
inftruments, and every other expence ; and Swammerdam’s wonderful {kill was 
day and night employed in making proper ufe of them. It was at this time, 
and on the twenty-fecond of January m pcixvit, that in Van Horne’s own houfe, 
Swammerdam firft injected the uterine veffels of a human fubject with a 
ceraceous matter, which moft ufeful attempt he afterwards improved and 
perfe@ed. The twenty-fecond of February of the fame year, he was admitted 
to his degrees as doétor of phyfic, after having publickly maintained his 
diatriba or thefis on refpiration ; which was then conceived but in fhort and 
contracted arguments, but appeared the March following with confiderable 
additions in a volume from the printing-houfe of Gafbekios, with a dedication 
to the illuftrious Thevenot, and adorned with a frontifpiece of a moft oceans 
gure 
