146 Scientific Intelligence. [Aug. 



other salt whatever. The following is the method which has 

 constantly succeeded with me. 



Take any quantity of strong acetic acid (what I used contained 

 about 35 per cent, of pure acid), put it into a tall cylindrical glass 

 vessel, and throw into it dry carbonate of ammonia in powder 

 till it ceases to effervesce, and is saturated with the ammonia. 

 Put the clear liquor thus obtained, which is a concentrated solu- 

 tion of acetate of ammonia in water, into a Wedgewood evapo- 

 rating dish, and enclose it in the exhausted receiver of an 

 air-pump a few inches above the surface of a flat glass dish, 

 containing a quantity of concentrated sulphuric acid. In two 

 or three days, the excess of water will be evaporated, and the 

 acetate of ammonia will be found crystallized in long needles, 

 not unlike the appearance of nitrate of ammonia. The salt tastes 

 slightly of acetic acid ; but hardly reddens litmus paper. 



This method would probably answer for crystallizing citrate 

 of ammonia and some other salts, which do not yield crystals 

 in the common way without considerable difficulty. 



IV. Urine of the Sow. 



The urine of this animal has been subjected to an analysis by 

 M. Lassaigne. 



It is transparent, slightly yellow, without smell, and having a 

 disagreeable but not a saline taste. 



Lime-water occasions a slight precipitate of carbonate of lime. 



Nitrate of baiytes and nitrate of silver indicate the presence of 

 sulphuric and muriatic acids. 



Potash occasions no precipitate ; but disengages ammonia. 



Oxalate of ammonia occasions a slight white precipitate. 



Infusion of nut-galls throws down yellow flocks. 



The following were the substances extracted from this urin« 

 by M. Lassaigne : 



1. Urea. 



2. Muriate of ammonia. 



3. Muriate of potash. 



4. Muriate of soda. 



5. Sulphate of potash. 



6. A little sulphate of soda. 



7. A trace of sulphate and carbonate of lime. 



(Jour, de Pharm. April, 1819, p. 174.) 



V. Gum Bassora. 



This is a species of gum, or rather of cerasin, well known in 

 France, and other parts of continental Europe, though unknown 

 in Great Britain, at least by that name. It comes, as the name 

 imports, from Persia, and is said to be produced in the sandy 

 plains of Arabia from different species of Mesembryanthemum, 



