of ammonia density 0.93 and 10 grams of zinc dust, which was 

 boiled with 5 grams of benzo})lienoiie. 



After 2 and 57^ hours' boiling, rcsi)ectiveiy 4.21 —4.34 grams of 

 pure lij^drole were formed ; the balance consisted of pinacone, which 

 could be isolated by the extraction of the insoluble part with benzene. 



After 2 hours 'nearly all the ammonia was boiled oft'; after 57.^ 

 hours it had quite disappeared. 



B. With aluminium amalgam. 



For 5 grams of ketone were taken 40 cc, of alcohol, JO cc. of 

 ammonia and 10 grams of aluminium amalgam and the whole was 

 boiled nntil all the ammonia was expelled (3 hours). 4.81 gi'ams of 

 very beantiful benzhydrole and 0.21 gram of pure pinacone were 

 obtained. 



From this we notice that the reduction is almost independent of 

 the metals and that the result is mainly governed by the reaction 

 of the medium. 



5. In a stronger alkaline medium with alcoholic sodium hydroxide 

 not a trace of i)inacone was obtained, with zinc dust as well as 

 with aluminium; the product was very readily soluble in 80 7» ^1^'ohol. 

 During the aluminium reduction, which was particularly violent, a 

 product was obtained having a pale yellow colour and which Jud- 

 ging from the odour, contained a little diphenylmethane. 



I^et us tabulate the results obtained in the subjoiued survey (also 

 including sodium). 



