ASELLIUS 15 



of his contemporary. In a private letter written in April, 1652, he 

 writes : 



"With regard to the lacteal veins discovered by Aselli, and by the further 

 diligence ot! Pecquet, who discovered the receptacle or reservoir of the chyle, 

 and traced the canals thence to the sub-clavian veins, I shall tell you freely, since 

 you ask me, what I think of them. I had already, in the course of my dissections, 

 I venture to say even before Aselli had published his book, observed these white 

 canals. * * * But, for various reasons, and led by several experiments, I 

 could never be brought to believe that that milky fluid was chyle, conducted thither 

 from the intestines, and distributed to all parts of the body for their nourish- 

 ment; but that it was rather met with occasionally and by accident, and proceeded 

 from too ample supply of nourishment and a peculiar vigor of concoction ;" and 

 Harvey continues: "Why indeed, should we not as well believe that the chyle 

 (digested contents of the intestines) enters the mouth of the mesenteric veins 

 and in this way becomes immediately mingled with the blood, where it might 

 receive digestion and perfection. * * * And that the thing is so in fact, I 

 find an argument in the distribution of innumerable arteries and veins to the 

 intestines, more than to any other part of the body, in the same way as the 

 uterus abounds in blood vessels during the period of pregnancy." 



Sir William Osier) (Harveian oration, 1906) refers to this inci- 

 dent in Harvey^s'career: **How eminent so ever a man may become 

 in science, he is very apt to carry with him errors which were in^ 

 vogue when he was young — errors that darken his understanding^ 

 and make him incapable of accepting^-eveii_tha-most--0bviaus truths. 

 It is a great consolation to know that Harvey came within the range 

 of this law — in the matter of the lymphatic system; it is the most 

 human touck in his career." 



Th^ lacteals were demonstrated in man in 1628, the subject be- 

 ing an executed criminal examined shortly after execution. Twenty- 

 one years after Aselli's death the thoracic duct was discovered by 

 Johannes Pecquet, of Dieppe, France. He not only accurately de- 

 scribed these lymphatic structures, but showed that Aselli's lacteals 

 poured their contents into what he called the receptaculum chyli, but 

 that the thoracic duct — a continuation of the receptacle — poured its 

 contents into the venous system at the junction of the jugular and 

 subclavian veins. Pecquet was twenty-five years old when he made 

 this discovery, which he himself described as the gift of fortune 

 sporting with the ignorant. Munus est fortunae cum inscio ludentis. 

 Pecquet, however, did not follow up this solitary triumph. His ap- 

 petite for alcoholic beverages got the better of him and eventually 

 caused his death. 



Harvey's work on the circulation appeared between the discov-] 

 ery of Aselli and that of Pecquet and so profoundly had it influenced^ 

 the medical thought of the time, that the discovery of the thoracic) 

 duct and its function was accepted without question. y 



