654 PHILOSOPHICAL TRANSACTIONS. [aNNO I789. 



in Boutan. The high winds, sandy soil, and glare from the reflection of the 

 sun, both from the snow and sand, account for this. I have dwelt long on this 

 subject, because I think the knowledge and observations of these people on the 

 diseases of their country, with their medical practice, keep pace with a refine- 

 ment and state of civilization, which struck me witlj wonder, and no doubt will 

 give rise to much curious speculation, when known to be the manners of a 

 people holding so little intercourse with what we term civilized nations. ^ 



Dec. 1 . Left Tishoolumbo, and found the cold increase every day as we ad- 

 vanced to the southward, most of the running waters frozen, and the pools 

 covered with ice strong enough to carry. Our thermometer having only the 

 scale as low as l6°, we could not precisely determine the degree of cold, the 

 quicksilver being under that every morning. The frost is certainly never so in- 

 tense in Great-Britain. On our return to the lakes the 14th, we found them 

 deserted by the water fowl, and were informed that they had been one solid 

 piece of ice since the 10th of November. Here we resumed our amusement of 

 skating, to the great astonishment of the natives and Bengal servants. 



On the 17th we re-entered Boutan, and in 6 days more arrived at Punukha by 

 Paraghon. No snow or frost to be met with in Boutan, except towards the tops 

 of their highest mountains; the thermometer rising to 36° in the morning, and 

 48° at noon. Took leave of the Debe Rajah, and on the 12th arrived at Buxa- 

 duar. Calcutta, Feb. 17, 1784. 



As Lac is the produce of, and a staple article of commerce in Assam, a 

 country bordering on and much connected with Thibet, some account of it may 

 not be an improper supplement to the above remarks. Lac is, strictly speaking, 

 neither a gummy nor resinous substance, though it has some properties in com- 

 mon to both. Gums are soluble in water, and resins in spirits; lac admits of a 

 very difficult union with either, without the mediation of some other agent. 

 Lac is known in Europe by the different appellations of stick lac, seed lac, and 

 shell lac. The first is the lac in pretty considerable lumps, with much of the 

 woody parts of the branches on which it is formed adhering to it. Seed lac is 

 only the stick lac broke into small pieces, garbled, and appearing in a granulated 

 form. Shell lac is the purified lac, by a very simple "process to be mentioned af- 

 terward. 



Many vague and unauthenticated reports concerning lac have reached the 

 public; and though among the multiplicity of accounts the true history of this 

 substance has been nearly hit on, little credit is given in Europe to any descrip- 

 tion of it hitherto published. My observations, as far as they go, are the result 

 of what I have seen, from the lac on the tree, the progress of the insect now in 

 my custody, and the information of a gentleman residing at Goalpara on the 

 borders of Assam, who is perfectly versant in the method of breeding the 

 insect, inviting it to the tree, collecting the lac from the branches, and forming 



