254 Intelligence and Miscellaneous Articles. 



on cooling, a bright, brownish, very acid liquor, which must be care- 

 fully filtered to deprive it of a deposit of a dirty white colour, formed 

 during concentration. The liquid is again evaporated, with a gentle 

 heat, to the consistence of a syrup, and then nearly to dryness, in 

 vacuo, over some substance powerfully attractive of water. The re- 

 sidue is to be put into a stoppered glass bottle, and there are to be 

 added to it cold, ten or twelve times its weight, of a mixture of two 

 parts of sulphuric aether and one part .of rectified alcohol ; it is to be 

 often shaken, and, after some days, the liquid, which has acquired 

 an amber colour, is to be poured off; this liquid is very acid, and is 

 to be shaken in a bottle, with a slight excess either of the carbonate 

 of lime, of zinc, or of barytes, or bicarbonate of potash. From their 

 reaction effervescence results, and there are produced lactate and 

 phosphate of lime, zinc, barytes, or potash, by the saturation of the 

 free lactic and phosphoric acid, which the urine contains. 



The liquid aethereal portion, again filtered and exposed to a very 

 gentle heat, soon yields in both cases, very fine prismatic crystals of 

 lactate of urea, perfectly similar to those artificially prepared. These 

 crystals are long transparent hexagonal prisms, have a sharpish taste, 

 are volatile at a moderate heat, entirely decomposed when heated to 

 redness on platina foil, very soluble in water, alcohol, and alcoholized 

 aether, but less so in sulphuric aether. They attract moisture from 

 the air powerfully, dissolve entirely in it, and form a bright coloured 

 solution, which, when gently heated, again furnishes crystals. Oxalic 

 and nitric acids form, when added to the solution, either laminated 

 crystalline precipitates, or pearly acicular crystals. Hydrate of lime 

 does not disengage ammonia, as immediately occurs with ammoniacal 

 salts. In order to determine the state of combination of the lactic 

 acid with the urea, the following experiments were made : — A quan- 

 tity of the crystals obtained by the spontaneous evaporation of alco- 

 holized aethereal liquor, were pressed on filtering paper, and divided 

 into three equal portions, A, B, C. 



A. These crystals, dissolved in pure water, were slightly heated 

 with an excess of hydrate of zinc, recently prepared and dried by 

 exposure to the air. The mixture was carefully evaporated to dry- 

 ness, and treated with hydrated sulphuric aether, which dissolved the 

 urea, and yielded it, after evaporation in the air, in crystals which 

 were not hygrometric. The residue, not acted upon by this, was 

 treated with hot distilled water, filtered and evaporated on a sand 

 bath. This operation yielded white acicular styptic crystals of lactate 

 of zinc. 



B. Another portion of the crystals was treated with a solution of 

 barytes ; it was evaporated to dryness, and treated successively with 

 sulphuric aether and weak alcohol. The aether dissolved the pure 

 urea, and the alcohol dissolved the dry lactate of barytes ; it was 

 very soluble, decomposable by heat, and precipitated sulphates like 

 other barytic salts. 



C. Lastly, to the third portion of the crystals, dissolved in a small 

 quantity of water, oxalic acid was added till the crystalline precipi- 

 tation of oxalate of urea ceased. The solution was carefully evapo- 



