VOL. LXXI.] PHILOSOPHICAL TRANSACTIONS. 127 



lac, strain it through a cloth, and let it boil for a short time, then add half an 

 ounce of soap earth (fossil alkali); boil an hour more, and add 3 ounces of 

 powdered load (bark of a tree) ; boil a short time, let it stand all night, and 

 strain next day. Evaporate 3 quarts of milk, without cream, to 1 quarts, on a 

 slow fire, curdle it with sour milk, and let it stand for a day or two; then mix 

 it with the red liquid abovementioned ; strain them through a cloth, add to the 

 mixture 1 ounce and a half of alum, and the juice of 8 or 10 lemons: mix the 

 whole, and throw it into a cloth-bag strainer. The blood of the insect forms a 

 coagulum with the caseous part of the milk, and remains in the bag, while a 

 limpid acid water drains from it. The coagulum is dried in the shade, and is 

 used as a red colour in painting and colouring. 



Dyeing. — Take 1 gallon of the red liquid prepared as before without milk, to 

 which add 3 ounces of alum. Boil 3 or 4 ounces of tamarinds in a gallon of 

 water, and strain the liquor. Mix equal parts of the red liquid and tamarind 

 water over a brisk fire. In this mixture dip and wring the silk alternately till it 

 has received a proper quantity of the dye. To increase the colour, increase the 

 proportion of the red liquid, and let the silk boil a few minutes in the mixture. 

 To make the silk hold the colour, they boil a handful of the bark called load in 

 water, strain the decoction, and add cold water to it; dip the dyed silk into this 

 liquor several times, and then dry it. Cotton cloths are dyed in this manner; 

 but the dye is not so lasting as in silk. 



Spanish wool. — The lac colour is preserved by the natives on flakes of cotton 

 dipped repeatedly into a strong solution of the lac insect in water, and then 

 dried. 



XXV. Account of a Phenomenon observed on the Island of Sumatra. By 



William Marsden, Esq. p. 383. 

 In the year 1775 the s. e. or dry monsoon, set in about the middle of June, 

 and continued with very little intermission till the month of March in the fol- 

 lowing year. So long and severe a drought had not been experienced there in 

 the memory of the oldest man. The verdure of the ground was burnt up, the 

 trees were stripped of their leaves, the springs of water failed, and the earth 

 every where gaped in fissures. For some time a copious dew falling in the night 

 supplied the deficiency of rain; but this did not last long: yet a thick fog, 

 which rendered the neighbouring hills invisible for months together, and nearly 

 obscured the sun, never ceased to hang over the land, and add a gloom to the 

 prospect already but too melancholy. The Europeans on the coast suffered 

 extremely by sickness; about a 4th part of the whole number being carried off by 

 fevers and other bilious distempers, the depression of spirits which they laboured 



