442 
EFFECT OF POISONING THE FCETUS. 
between the foetal and the maternal portions of the placenta, 
speaks of the one being 4 probably designed to separate from 
t lie blood of the parent the materials destined for the blood of 
the foetus/ while the other 4 probably serves for the absorp- 
tion of the material secreted by the other set of cells, and for 
its conveyance into the blood-vessels of the foetus’ — no idea, 
seemingly, being entertained of a converse process.* More- 
over, the view taken by most physiologists of the destination 
of that portion of the foetal blood which is transmitted to the 
placenta appears to be exclusively that of renovation or 
aeration, by coming into relation with the oxygenated blood 
of the mother, nothing being said as to re-absorption into the 
maternal system.” In a note he adds, 44 In his 4 History of 
Medicine/ Dr. Alison expresses himself even more strongly 
on the subject: 4 The experiments of Magendie and others 
have proved that any substance which may be circulating in 
the blood of the mother finds ready access to that of the 
foetus, but that there is little or no transference of fluids 
in the opposite direction.’ ” Those authors who express a 
contrary opinion, cannot refer to apy facts in support of it. 
As the question at present stands, then, the only demon- 
strative evidence is that yielded by the experiments of 
Magendie, and these gave a negative answer. All the rest of 
the evidence which has been adduced on either side is devoid 
of proof, is indirect and inconclusive. 
This subject was brought before the notice of the Hun- 
terian Society by Mr. Jonathan Hutchinson, in a paper on 
the 4 Communication of Syphilis from the Foetus to the 
Mother/ read there in the latter part of 1856.f It was fol- 
lowed by a very interesting discussion, and it then occurred 
to me that it should be brought to the test of experiment. 
* It is, however, only fair to add that in the later editions of his wGrk, 
Dr. Kirkes in a rote expresses the following strong opinion : “ Although 
in the text mention is made only of the passage of materials from the 
blood of the mother into that of the foetus, yet there can be no doubt of 
the existence of a mutual interchange of materials between the blood of 
both foetus and parent, the latter supplying the former with nutriment, aud 
in turn abstracting from it materials which require to be removed. 5 ’ The 
most recent expression of Dr. Carpenter’s opinion is to this effect. After 
giving the common account of the function of the placenta as furnishing 
materials for the nutrition of the embryo and as a respiratory organ, he 
adds, “ And it is probable, too, that the placenta is to be regarded as an 
excreting organ, serving for the removal, through the maternal blood, of 
excrementitious matter, whose continued circulation in the blood of the 
foetus would be prejudicial to it.” 
-j* This question in relation to the transmission of syphilis had previously 
been often suggested by various authors, but it is much more fully dis- 
cussed by Mr. Hutchinson. 
