RESPIRATION OF THE FOETUS. 227 



same thing at Paris, in an incontestible manner, in 1825, accor(^ng 

 to the report of M. Marc; M. Hesse has related a fifth case; and 

 M. Lesauvage assures ns that he very distinctly heard the cries of 

 young puppies while still in their mother's belly. 



584. When the membranes are ruptured and the watery discharged, 

 when the orifice is dilated, and the child's face engaged more or 

 less deeply in the excavation, we may conceive, indeed, that the foetus 

 might breathe and utter some cries before its complete expulsion; 

 but still the state of compression and constraint of the thorax ren- 

 ders the possibility of such an occurrence very doubtful; but when 

 the ovum is entire, as in the case given by M. Lesauvage, the fact is 

 so improbable, that we are not authorised to draw any conclusions 

 from it. 



It is sometimes so difficult to avoid all the causes of error, 

 all subterfuges, not to be deceived by strange and unexpected 

 noises, such for example as are often produced by air in the 

 intestines, that before we admit as positive a phenomenon which 

 it is impossible to reconcile with the laws of physiology, the 

 same person should have ascertained its existence repeatedly; in 

 the mean time, I may say with Fontenelle, that, since learned and 

 credible men have heard it, I will believe it, but I should not believe 

 it if I had heard it myself. 



585. Further, if the foetus really breathed; if air passes through 

 its lungs, they would be permeable and spongy, while at birth they 

 are, as is well known, quite compact, and as heavy as a slice of mus- 

 cular tissue. 



§. IV. Of the \*iability of the Foetus. 



586. The word viability, derived from via, is employed in medi- 

 cal jurisprudence to express the possibility of passing through the 

 various phases of' human life. To render a child viable, it should 

 possess at birth an aptitude to live independently of its mother; 

 from this definition it will be perceived that a foetus at term, as has 

 been remarked by M. Billard, may be born not viable, provided it be 

 affected with some faults of conformation, or with certain diseases, 

 as also that a foetus may be born viable although dead when passing 

 from its mother's womb. 



At what stage of pregnancy is viability possible? Although 

 debated by accoucheurs and physicians in all ages and countries, this 

 question has continued until this moment undecided. The foetus 

 which according to some persons is viable at four months and a half, 

 does not, according to others, really enjoy viability until the seventh 

 month. 



