2oo Letters 



bearer of this letter), I entreat you very earnestly that 

 you will be pleased most kindly to favour him with any 

 assistance or advice of which he may stand in need. 

 For thus will you indeed do that which will be very 

 gratifying to me. Farewell, most accomplished sir, and 

 deign to cherish the memory of our friendship, as does 

 most truly the admirer of all your virtues, 



WILLIAM HARVEY. 



London, Oct. 25th, in the year of the Christian era, 1655. 



LETTER IX 



To the distinguished and accomplished John Vlackveld, 



Physician at Harlem 



LEARNED SIR, Your much esteemed letter reached 

 me safely, in which you not only exhibit your kind 

 consideration of me, but display a singular zeal in the 

 cultivation of our art. 



It is even so. Nature is nowhere accustomed more 

 openly to display her secret mysteries than in cases 

 where she shows traces of her workings apart from the 

 beaten path ; nor is there any better way to advance 

 the proper practice of medicine than to give our minds 

 to the discovery of the usual law of nature, by the 

 careful investigation of cases of rarer forms of disease. 

 For it has been found in almost all things, that what 

 they contain of useful or of applicable, is hardly per- 

 ceived unless we are deprived of them, or they become 

 deranged in some way. The case of the plasterer J to 

 which you refer is indeed a curious one, and might 

 supply a text for a lengthened commentary by way of 



[' Valkveld had sent to Harvey the particulars of a case of diseased 

 bladder, in which that viscus was found after death not larger than " a 

 wainut with the husk," its walls as thick as the thickness of the little 

 finger, and its inner surface ulcerated.] 



