94 The Potatoe Plague. 
eaten when they have a sufficiency of alkalies, for by their 
aid they form carbonate of lime, phosphate of lime, silicate of 
potash, &c., and make their stalks and leaves so hard and 
strong as to be almost impenetrable to the attacks of many 
insects that infest them. And their juices are so insipid that 
they are not so well relished by such insects. 
