THE 

 LONDON, EDINBURGH and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[THIRD SERIES.] 



NOVEMBER 1844. 



LI. Examination of a yello'w substance from India called 

 Purree, from 'which the pigment called Indian Yellow is 

 manufactured. By John Stenhouse, Ph.D.^ 



pURREE, the substance from which the well-known pig- 

 ■*- ment, Indian yellow, is made, is imported into Great 

 Britain in considerable quantity from various parts of India 

 and China. As usually met with in commerce, purree con- 

 sists of balls of from three to four ounces in weight, which are 

 dark brown externally, but when broken up their interior has 

 a deep orange colour. "When viewed under the microscope, 

 they evidently consist of small needle-shaped crystals. Purree 

 has a very peculiar smell, very closely resembling that of 

 castor. This circumstance has induced the belief that it is an 

 animal matter, and it is generally regarded, even by those best 

 acquainted with the East, as consisting of bezoars from the 

 gall-bladders of different animals, such as the Camel, the Ele- 

 phant, the Buffalo, &c. Another prevalent opinion is, that it 

 is a deposit from the urine of some of these animals. From 

 reasons which will presently appear, I am induced to believe 

 that purree has a vegetable and not an animal origin. My 

 attention was first directed to it by Dr. Pereira, and through 

 the kindness of Messrs. Warington and W. De la Rue I was 

 enabled to obtain a quantity of it for examination. 



Purree is not very soluble either in water or in alcohol; its 

 aqueous solution has a pale yellow colour, and is quite neu- 

 tral. JEither also dissolves a little of it, and on evaporating 

 the solution a bright yellow crystalline matter is deposited, 

 which is slightly acid. Caustic alkalies dissolve a portion of 

 it; their solutions have a fine rich yellow colour, but even 

 when boiled with it not a trace of ammonia is evolved. When 

 purree is burned it leaves a considerable quantity of ashes, 

 * Communicated by the Author. 



Phil. Mag. S. 3. Vol. 25. No. 167. Nov. IS^*. Y 



