Improvements in Science. 295 



the chlorine has ceased, it is necessary to take up the oily 

 matter with the ether, and to dissolve the residue in this 

 liquid with heat in a closed flask, and to crystallize by cool- 

 ing. Boiling sulphuric acid converts it, 1st, into a matter 

 insoluble in water, and soluble in ether. When this solution 

 is evaporated a transparent varnish is left. 2d. Another 

 substance which remains in solution and gives, withbarytes, 

 an incrystallizable salt soluble in alcohol, which is probably 

 a sulpho-salt analogous to the sulpho-naphthalates. Hydro- 

 chlorate of chloro-naphthalese consists of carbon 44*79, 

 hydrogen 2-70, chlorine 52*51. 



8. Bromo-naphthalase. — When a few drops of bromine 

 are poured upon naphthaline a lively action ensues, heat 

 and hydrobromic acid are disengaged, and an oily product 

 is formed. This consists of carbon 50*9, hydrogen 2*9, 

 bromine 46*2. This oil is evidently a mixture of two 

 substances, the first of which has not been separated, but 

 the second. 



9. Bromo-naphthalese may be obtained by distilling a 

 mixture of bromine and naphthaline. Hydrobromic acid, 

 a bromine oil, and charcoal come over, and towards the 

 end of the process crystals of bromo-naphthalese appear. 

 These are formed most completely when the bromine has 

 been added in excess to the naphthaline. In dissolving 

 this product in alcohol and evaporating, we obtain six-sided 

 prismatic needles. They are white, insoluble in water, 

 volatile, very soluble in alcohol and ether. They consist of 

 carbon 42*9, hydrogen 2*1, bromine 55. 



10. Bromide of chloro-naphthalese is formed by pouring 

 bromine upon chloro-naphthalese in a close flask. The 

 latter dissolves and solidifies into a crystalline mass. When 

 purified by alcohol it resembles the chloride of chloro- 

 naphthalese, and consists of carbon 23*5, hydrogen 1*05, 

 chlorine and bromine 74*45. 



1 1 . Nitro-naphthalase is formed by the action of boiling 

 nitric acid upon naphthaline. A new oil is obtained first, 

 which solidifies very slowly by cooling, forming a crystal- 

 line mass of large needles. It consists of two bodies very 

 soluble in alcohol and ether, the one is solid or nitro-naph- 

 thalase, the other is liquid. The former is expressed be- 

 tween folds of paper. It is then dissolved in alcohol. On 



