397 



and twelve inches deep, respectively, the amount of phosphoric 

 acid present increases with the depth at which the sample is taken, 

 and it is possible therefore that at still greater depths material 

 richer in phosphoric acid than the best of these samples may be 

 obtained. 



COMMERCIAL VALUATION. 

 Samples of the four guanos were submitted to dealers in guano, 

 who were also informed of the results of their chemical examination, 

 for commercial valuation. They stated that large deposits of bat 

 guano occur in Mexico, Borneo, Algeria, Jamaica and elsewhere, 

 and that small consignments, similar in composition to those how 

 sent from the Federated Malay States, had occasionally been sent 

 to this country, but that the material had not been received with 

 favour, and there was reason to believe that these shipments had 

 nof proved remunerative to the exporters, and as a result no regular 

 trade in this product has become established. The Imperial Insti- 

 tute will be glad to supply any further information regarding 

 methods of utilising these products which may be required. 



WYNDHAM R. DUNS FAN. 



2yd June, 1905. 



IMPERIAL INSTITUTE. 



(SOUTH KENSINGTON, LONDON, S. W.) 



REPORT ON SAMPLES OF PATCHOULI AND 

 * CITRONELLA OILS FROM PERAK, MALAY 

 PENINSULA. 

 BY 



Professor Wyndham R. Dunstan, m.a., f.r.s., Director. 



These two samples of volatile oils were forwarded to the Impe- 

 rial Institute by Mr. W. K. SMITH, of the Kellas Estate, Perak, 

 together with a letter dated the 21st December, 1904, at the sug- 

 gestion of the Superintendent of the Botanic Gardens, Singapore, 

 and it was requested that they might be examined and their quality 

 and commercial value ascertained. 



CITRONELLA OIL. 

 Description of Sample. 



The sample measured about four fluid ounces and was labelled 

 "Citronella Oil, distilled on the Kellas Estate, 20th December 

 1004." The oil was of a pale yellow colour and possessed the 

 characteristic fragrant odour of citronellal ; it was quite clean and 

 free from water. 



Chemical Examination. 

 The oil was chemically examined in the Scientific and Jechnlg 

 Department of the Imperial Institute, and gave the re sulU rword 

 in the following table, which also gives, for convenience of com 



