360 THE SECRETIONS: 



to the action of cold. Verrucose crystals then separated them- 

 selves, which were assumed to be composed of nitrate of urea, 

 without being further analysed. 



The salts of the liquor amnii are described as consisting of 

 chloride of sodium in large quantity, phosphate, sulphate, and 

 carbonate of soda, sulphate of lime, and a small amount of 

 potash-salts. 



The analyses of Voigt, which were made with the liquor amnii 

 of women who had died in various stages of pregnancy, give 

 discordant results, probably as Berzelius supposes from the cir- 

 cumstance of the fluid at the full time being different from 

 what it was in the early stages of pregnancy. The liquor amnii 

 at the fourth month was not turbid, had an insipid taste, a 

 specific gravity of 1018-2, a neutral reaction, frothed upon 

 being shaken, coagulated on boiling, was precipitated by bi- 

 chloride of mercury and tannic acid, and less copiously by 

 perchloride of iron and acetate of lead. After coagulation by 

 boiling, the fluid which had been cleared by filtration, was 

 strongly precipitable by nitric acid, while it was very little 

 affected by chloride of barium, lime-water, ammonia, or oxalate 

 of ammonia. Perchloride of iron, and chloride of platinum, 

 produced no effect upon it. 



The liquor amnii at the sixth month was turbid, yellowish, 

 viscid, had a specific gravity of 1009'2; when heated to the 

 boiling point gave a mucous coagulum which could not be se- 

 parated by filtration, and its behaviour towards reagents was 

 the same as in the former case. As to casein, ptyalin, urea, 

 benzoic and hippuric acids, Voigt was as unable to find them 

 as carbonate of ammonia or sulphuret of ammonium, and he 

 conceives that at least some of these substances may arise from 

 the foetal urine which becomes mixed with the liquor amnii 

 previous to delivery. Voigt' s view of the composition of the 

 liquor amnii is as follows : 



At the 4th month. At the 6th month. 



Water . . . 979-45 990-29 



Alcohol-extract and lactate of soda 3-69 0-34 



Albumen . . .10-77 6-67 



Chloride of sodium . . 5-95 2-40 



Sulphate and phosphate of lime . 0-14 0-30 



