THE WORK OF THE FOREST DEPARTMENT IN INDIA. 37- 



show that wintergreen oil can be distilled at a profit in India 

 from the leaves of Gaultheria fragrantissima collected in Assam 

 during the winter. The fresh leaves gave as much as 0-65 per 

 cent, of oil, or 1-2 per cent, calculated on the dry material. The 

 Nilgiri plant gave only 0-12 per cent, of oil from fresh leaves 

 and 0-23 per cent, calculated on dry material. The plant grows 

 gregariously in the Nilgiris, in Assam and in Ceylon, but for a 

 regular supply of the leaves it would be necessary to cultivate 

 it on an extensive scale. From the wintergreen oil so distilled 

 it has been shown that natural salicylic acid and natural sodium 

 salicylate can be easily prepared. 



(ii) Oleoresins. 



Pine resin is by far the most important oleoresin obtained' 

 from the forests of India, and as its collection has now reached 

 the stage of an important industry it is dealt with separately 

 below. Of other oleoresins the following deserve mention : — 



The gum-oleoresin of Balsamodendron Mukul (gugal). — 

 This is a useful product, yielding -05 per cent, of oil and 73-62 

 per cent, of a yellow resin similar to that obtained from Siam,„ 

 the so-called acroid resin used for metal polishing. It also 

 yields 13-66 per cent, of gum of an inferior quality. 



Boswellia serrata. — The gum-oleoresin of Boswellia serrata 

 may prove to be of considerable importance. Unlike the pine 

 oleoresins, it is made up of three ingredients (1) an oil, (2) a 

 rosin, and (3) a gum. Though it was known that the oil of 

 myrrha and this gum-oleoresin resemble each other and that 

 both contain pinene, it is only recently that an attempt has been 

 made to isolate these ingredients commercially. The enquiry 

 was initiated by the Forest Research Institute, and after muchi 

 work and with the help of the Imperial Institute, a process for 

 the isolation of the products has been evolved. A full report 

 on the subject is under preparation, and though there are diffi- 

 culties to be overcome in connection with the collection of the 

 raw oleoresin there are good prospects for the establishment of 

 this industry on a commercial scale. 



Dipterocarp oleoresins. — The oleoresins of the Burma dip-^ 

 terocarps have received little attention from chemists up to- 



