AMYL SERIES OF COMPOUNDS. 811 



in four-sided prisms, terminated by summits truncated obliquely; 

 they contain 3 atoms of water. Alcohol produces in the aque- 

 ous solution a white precipitate of a basic salt, which dissolves 

 in water and crystallizes ; it appears to contain 3 atoms of 

 oxide of zinc. Lactate of magnesia crystallizes in small plates, 

 containing 3 atoms .of water ; it dissolves in 30 parts of cold 

 water. The lactates of alumina,, nickel) lead and mercury are 

 very soluble in water, arid do not crystallize in a regular 

 form. Lactates of protoxide of iron, FeO,L+3HO, of oxide of 

 copper^ CuO,L + 2HO, and of silver are crystallizable. 



Lactate of urea was discovered by MM. Cap and Henry in 

 urine. It may be formed artificially by the double decompo- 

 sition of lactate of lime and oxalate of urea, the oxalate of lime 

 being separated by a filter, and the liquid evaporated by a gentle 

 heat. The evaporation is terminated in vacuo near concentrated 

 sulphuric acid. Lactate of urea crystallizes in colourless hexago- 

 nal needles, of a sharp and cooling taste, which are deliquescent. 

 At a moderate heat it enters into fusion, and sublimes without 

 alteration. Lactate of urea differs from the oxalate and nitrate 

 of urea in not containing 1 atom of water of combination which 

 these possess. 



SECTION X. 



OIL OF GRAIN- SPIRITS OR FOUSEL OIL, AND BODIES DERIVED 

 FROM IT. 



AMYL SERIES OF COMPOUNDS. 



Amyl, C 10 H u = Ayl ; the hypothetical radical of a series of 

 compounds, of which the hydrate of the oxide has long been 

 known as f ousel oil, or as the oil of grain-spirits or potatoes, 

 as it is produced in the fermentation of unmalted grain 

 and potatoes, along with alcohol, and distils over with the 

 latter. It has been studied very fully by M. Cahours (An. 

 de Chim. &c. Ixx. 81, and Ixxv. 193). There is every rea- 

 son for considering this body as an alcohol, the most striking 

 analogy existing between oil of potatoes and ordinary alcohol. 

 This will be made sufficiently evident by the following table, in 

 which the corresponding compounds of the ethylic and amilic 

 series are compared : 



