218 Dr. Robert J. Kane on the 



ley remains clear, we may conclude that it is caustic ; but, 

 if a milkiness and flocky precipitate should appear, it is not 

 caustic. 



In order that we may not be deceived in this test, it is 

 always necessary to drop the ley into the lime water, but 

 not inversely the water into the ley. Some employ sul- 

 phuric acid for the same purpose, and consider a ley com- 

 pletely caustic, if, when dropped into dilute sulphuric acid, 

 it does not effervesce. But when the effervescence proceeds 

 from the carbonic acid, the latter being soluble in dilute 

 sulphuric acid, this test is not quite certain. 



Very strong caustic leys are prepared by boiling down 

 weaker leys in an iron boiler, (whereby the ley must always 

 be kept at a boiling temperature, or it will immediately ab- 

 sorb carbonic acid from the air), or from the ashes of the 

 soap boiler. It is allowed to dissolve the alumina in the 

 exhibition of the alkaline aluminous mordant, and for the 

 production of manganese bistre. Caustic leys dissolve oil, 

 forming a clear solution, and producing soap. If, on the 

 other hand, the ley is not caustic, it combines equally with 

 the oil, but the solution is milky and the oil readily sepa- 

 rates again. This combination (oil mordant) is of great use 

 in dyeing Turkey-red, as will subsequently appear. 



Potash cannot be printed upon cotton any better than 

 caustic ley. In the first place, the thickening is effected 

 with difficulty, although, to a certain extent, it succeds 

 well with strong gum. Secondly, potash has a great ten- 

 dency to extract water from the air, and deliquesce. The 

 printed pattern, therefore, has not a regular edge, but a 

 border is formed. 



(To be continued. j 





Article VI. 



Action of Ammonia and Muriatic Acid. 

 By Robert J. Kane, M.D. 



(Extract from a Letter to Dr. Thomson.) 



The theory of the Amides which has been found of such in- 

 terest in organic chemistry, induced me to study the action 

 of ammonia upon various metallic compounds, and has led 



