FLUID OF THE ALLANTOIS. 363 



found no urea. It had a specific gravity of 1005*1, and left 

 a solid residue of 1'45, half of which was soluble in alcohol : 

 the portion which was not soluble in it consisted of albumen, 

 chloride of sodium, and sulphate of lime. 



In the liquor amnii of a cow, which was viscid, very thick, 

 of a yellow colour, and had a saltish taste and an alkaline reac- 

 tion, Lassaigne found albumen, mucus, a yellow matter analo- 

 gous to bile, chlorides of sodium and potassium, carbonate of 

 soda, and phosphate of lime : no extractive matters are enu- 

 merated amongst the constituents. The flocculi which are 

 suspended in the liquor amnii of the cow are said by this che- 

 mist to be composed of albumen with 0'27 of their weight of 

 oxalate of lime. 



I have already treated of vaginal mucus, menstrual blood, 

 and the secretion of the mammary glands ; it still remains for 

 me to offer a few remarks on the fluid of the allantois. The 

 allantois with its inclosed fluid is absent in the human em- 

 bryo: it is found, however, in many animals. It is situated 

 above the amnion, and it is between these two membranes that 

 the urine of the foetus collects, being conveyed there by the 

 urachus from the urinary bladder, and constituting the fluid of 

 the allantois. 



It has several times been the object of chemical investiga- 

 tion; it is clear, of a brown-yellow colour, of a bitter and saltish 

 taste, and reddens litmus paper. Its specific gravity, according 

 to Dzondi, fluctuates between 1003 and 1029. On evapora- 

 tion flocculi are precipitated, which consist of albumen and 

 phosphate of lime. The residue left after evaporation is very 

 slightly soluble in alcohol, which takes up a yellowish-brown 

 acid extractive matter, and white nacreous crystals which retain 

 their form upon mixing the residue obtained by evaporation with 

 water, and constitute allantoin, which was first termed by 

 Vauquelin, amniotic acid, and by Lassaigne, allantoic acid. 

 The substances remaining in the watery solution, are chloride 

 of sodium, alkaline lactates, a salt of ammonia, and extractive 

 matters. From the portion insoluble in alcohol, water takes up 

 sulphate and phosphate of soda, phosphates of lime and mag- 

 nesia, and a brown extractive matter which is copiously precipi- 

 tated by infusion of galls. Whether the fluid of the allantois 



