Italian doctor (1628–1694) who gave his name to several physiological features and played an important part in the discovery of the microscope and study of human physiology. Rare ALS in Italian, one page both sides, 5.25 x 8, December 15, 1691. In part (translated): "I am sorry about the obstinacy of the illness that is bothering the child of the most illustrious Countess Helen; it must be some defect in the lymph which troubles the chest and subsequently the entire organism. The remedies being used seem to me adequate, and the entire purpose must be directed to sweeten the humors, so that the chest will not be affected with a worse illness. One might also try the administration of goat whey in the quantity of four ounces. In the next solstice he will perhaps, as I desire, improve. Please give my best regards to the Illustrious Countess Helen...to the Illustrious Olimpia Fontana, also on behalf of my Francesca, who, and I thank God for this, is in good health." In very good to fine condition, with scattered overall light foxing, and nearly complete separation along the hinge. Published as letter 920 in Adelmann's Correspondence of Mercello Malpighi. Most Malpighi letters remain in institutional hands and rarely appear for sale.