Sentence:  Mix to a smooth batter the <WSD>arrowroot</WSD> with ½ pint of the milk; put the other pint on the fire, with laurel-leaves or lemon-peel, whichever may be preferred, and let the milk steep until it is well flavoured. Then strain the milk, and add it, boiling, to the mixed <WSD>arrowroot</WSD>; sweeten it with sifted sugar, and let it boil, stirring it all the time, till it thickens sufficiently to come from the saucepan. 
Meaning of the word marked with <WSD> tags:  A starchy substance obtained from the rhizomes of an arrowroot plant used as a thickener.