LAST SICKNESS 91 
Physician was wrong; for whilst the motion lasted, 
I off put my hand on my pulse, and could feel no 
quickening of its beat. This violent motion, returning 
at intervals, lasted for about three days; during which 
time my stomach and guts ceased to perform their office 
and motion, so that I was verily persuaded I stood at 
death’s door. 
In my opinion there was some obstruction, not less 
than a crown piece in bigness,’ stopping my diaphragm. 
On 31 May 1723 Leeuwenhoek actually sent the Royal 
Society a description of the histology of the diaphragm, which 
he had meanwhile studied (in sheep and oxen) in order to 
support the opinions expressed in the foregoing letter. And 
at the end of his account of the various muscles and tendons 
and vessels observable in the midriff he added :* 
Accordingly, the oftener I recall the foresaid distemper 
which seized me last winter, and which I attributed 
mostly to my diaphragm, the more am I of opinion that 
our Physicians are mistaken when they call that 
commotion, which we sometimes feel in the region of our 
chest, a palpitation of the heart. For my part, | am 
persuaded that such palpitations arise from a disorder 
of the Diaphragm; howbeit this may be brought about 
either by a deficiency of diet, or by obstruction of those 
blood-vessels which run through the diaphragm in great 
plenty. Such an obstruction can easily excite convulsive 
motions in the tendons aforesaid; and I believe this was 
the very cause of my own complaint. 
Towards the middle of August, 1723, Leeuwenhoek had 
another seizure; and now he was indeed—as he himself 
‘non minorem nummo imperialt MS. I take nummus imperialis to mean 
a rizksdaalder (—= 2% florins), which was roughly of the size and value of an 
English 5-shilling piece. 
* From Letter dated 31 May 1723. To the Royal Society. MS.Roy.Soc. 
Printed in full in Phil. Trans. (1723), Vol. XXXII, No. 379, p.400. Not 
in Dutch or Latin collective editions. Original MS. in Latin, from which 
I translate. 
