176 LYMPHATIC SYSTEM. 



vessels ; neither of which arguments are decisive. For there 

 may be lymphatics in the placenta, though not yet discovered ; 

 or there may be small vessels passing from the mother to the 

 foetus, though not yet injected. 



A sixth argument is furnished by the experiments of some 

 authors, in which experiments it is affirmed, that fluids injected 

 into the intestines were soon afterwards discovered in their 

 mesenteric veins. The experiment related by the ingenious 

 Kauw Boerhaave, has been the most depended upon in this 

 matter. 1 In which experiment water was injected into the 

 intestines, and those intestines being compressed, the water 

 was afterwards observed to run from the veins; but that 

 some fallacy had crept into this experiment is now probable, 

 from its having been repeated several times in a very satisfac- 

 tory manner, 2 without being attended with the like success. 

 The learned M. de Haller, indeed, in comparing these argu- 

 ments, says, that in such cases where authority seems to ba- 

 lance authority, he chooses rather to adopt the opinions of those 

 who affirm than of those who deny the fact. Eor, as he ob- 

 serves, this experiment may easily fail of success ; but if it has 

 ever succeeded, we shall not easily find another way of account- 

 ing for it, except by allowing that these veins open into the 

 intestines. 3 But, with due deference to the opinion of this 

 excellent author, Kauw Boerhaave's experiment is not so con- 

 clusive as those alluded to above; for in his, the dog was 

 opened immediately "after death, and water being injected into 

 his stomach, that water was seen first to dilute the blood, 

 then to wash it from the vena portarum, and the experiment 

 was continued a considerable time by means of pressing the 

 stomach, which pressure furnishes a strong presumption that 

 the water did not get into the veins by .absorption but by a 

 laceration, especially as the experiment continued to succeed 

 for some hours after death ; whereas absorption always ceases 

 long within the first hour. 4 This argument, therefore, which 



1 See De Perspir. 469-71. 2 Dr. Hunter's Medical Comm. chap. v. 



3 Elem. Phys. lib. xxiv, sect. 2, vi. 



4 K. Boerhaave's words (after mentioning that the blood was washed out by the 

 wound made in the auricle of the heart) are as follow : " Tandem pura aqua tsedioso 

 labore per horas, lenissime immittere aquam et premere ventriculum continuavi donee 

 pallerent omnia vasa sanguine orbata per resorptam aquam." See De Perspir. $ 470. 



