66 Experiments and Remarks on a Sid'sfanctt 



sulphuric acid, that a brown or reddish-brown solution i-3 

 formed, and that the camphor is precipitated unchanged 

 from this solution by water. These facts, however, only 

 relate to a certain period of the operation ; for, if this be long 

 continued, other effecls are produced, which I shall now 

 describe. 



A. To one hundred grains of pure cnmphor put into a 

 small glass alembic, one ounce of concentrated sulphuric 

 acid was added. The camphor immediately became yellow, 

 and gradually dissolved, during which the acid progressively 

 changed to brownish-red, and afterwards to brown. At 

 this period scarcely any sulphureous acid was evolved, but 

 in about one hour the liquid became blackish-brown ; 

 much sulphureous acid gas was then produced, and conti- 

 nued to increase during four hours, when the whole appeared 

 like a thick black liquid, at which period not any odour or 

 appearance of camphor could be perceived, but only that of 

 the sulphureous acid. After two days, during which time 

 the alembic had not been heated, there did not appear any 

 alteration, unless that the production of sulphureous gas 

 was much diminished. The alembic was then placed in a 

 sand-bath moderately warm, by which more of the sul- 

 phureous gas was obtained, but this also soon began to abate. 

 After the lapse of two other days, I added gradually six 

 ounces of cold water, by which the liquid was changed to 

 reddish-brown, a considerable coagulum of the same colour 

 subsided, the odour of sulphureous gas, which in some 

 measure had still prevailed, was immediately annulled, and 

 was succeeded by one which resembled a mixture of oils of 

 lavender and peppermint. 



The whole was then subjected to gradual distillation, 

 during which the water came over strongly impregnated 

 with the odour above mentioned, accompanied by a yel- 

 lowish oil, which floated on the top of it, and which, as far 

 as could be ascertained, amounted to about three grains. 



B. When the whole of the water was come over, there 

 was again a slight production of sulphureous gas. I then 

 added two ounces of water, which I drew off by distillation, 

 tut did not obtain any of the \'egetable essential oil which 



has 



