320 Intelligence and Miscellaneous Articles. 



the fluids contained in the amnios and allantois of the cow, and al- 

 ways found the acid in question in the fluid of the latter membrane, 

 but never in that of the former. He concluded from these results, 

 that the allantoic fluid had been given for analysis to Vauquelin 

 and Buniva, instead of the amniotic, and changed the name of the 

 acid accordingly. At present, therefore, our knowledge of the 

 true source of this acid rests upon the authority of Lassaigne alone. 

 But it is always desirable that new facts should not rest upon the 

 testimony of a single observer, however deservedly high may be 

 his reputation; and as the existence of strong independent, though 

 partial evidence, in favour of Lassaigne's conclusions, has apparently 

 been overlooked by that chemist (as well as by Dr. Thomson, though 

 published in the journal formerly conducted by himself), it may be 

 useful to draw the attention of chemists to the subject. This seems 

 the more requisite, because the authority ofX)r. Prout, by whom 

 the confirmatory evidence has been furnished, is so valuable upon 

 a point of this nature, on account of his minute acquaintance with 

 the animal fluids, and his practical skill in their examination ; and 

 because, also, the authors of several of our systematic treatises on 

 Chemistry (Dr. Henry and Dr. Turner for example,) have not no- 

 ticed Lassaigne's revision of the subject, but have retained the 

 amniotic acid, as such, in the sections on animal chemistry of their 

 respective works. 



In 1815 Dr. Prout published, in the Annals of Philosophy (First 

 Series, vol. v. p. 416), an account of his examination of the liquor 

 amnii of a cow. His attention, he states, in this examination, was 

 particularly directed to the principle found in that fluid by Vau- 

 quelin and Buniva, and called by them amniotic acid, but that he 

 could not, however, discover the least traces of a similar principle. 

 This negative result, therefore, confirms those of Lassaigne, who, 

 as above stated, could never find the acid in the fluid of the amnios. 



Further evidence, however, is derivable from Dr. Front's paper, in 

 confirmation of Lassaigne's opinion that the fluid examined by 

 Vauquelin and Buniva was truly that of the allantois. Dr. Prout 

 states that the fluid he examined differed very considerably from 

 that described by them, in its sensible qualities, as well as in its 

 chemical ones ; and although he ascribes this dissimilarity to the 

 circumstance that his was taken from an animal slaughtered in an 

 early period of her gestation, while theirs, most likely, he observes, 

 was procured at the full period, it is evident that the existence of 

 differences so great is far better explained, by the supposition, that 

 Vauquelin and Buniva in reality examined a different fluid, or at 

 least one which did not wholly consist of liquor amnii. A com- 

 parison of the results obtained by Vauquelin and Buniva with those 

 of Dr. Prout, tends rather to indicate that the fluid examined by 

 them consisted of the mixed fluids of the amnios and allantois, 

 than that it was the allantoic fluid alone, as supposed by Lassaigne. 

 Thus, the liquor amnii examined by Dr. P., as well as the fluid 

 examined by the former chemists, gave a copious white preci- 

 pitate with muriate of barytes ; both contained an organic sub- 

 ^, stance soluble in alcohol, and both also jj'ielded a substance pre- 



,';t8, ^-'Ci •^■ ,o'/I 



