298 VEGETABLE SUBSTANCES. 



juice, and use it in different states of concentration, 

 according to the purpose to which it is to be applied. 

 For most of the processes in calico-printing in which 

 citric acid is employed, it is found that the impurities 

 commonly found in lemon juice are of very little 

 consequence, and that when concentrated by driving 

 off its aqueous parts it very well answers for most 

 purposes, superseding the use of the crystallized acid. 

 Jn every large calico print-work there is always 

 abundance of spare heat, and therefore the evapora- 

 tion may be conducted without expense. There is, 

 however, a large consumption of citric acid for a 

 variety of other purposes, and it is therefore of con- 

 sequence that this should be obtained as cheaply as 

 possible. Fourcroy, in his ' General System of 

 Chemical Knowledge,' recommended the expediency 

 of sending proper persons to the French possessions 

 in America, in order to collect the vast quantity of 

 limes and lemons which were annually wasted there, 

 to saturate the expressed juice with chalk, and after 

 Washing and drying the citrate, to send it home 

 where it might be decomposed and the citric acid 

 obtained pure. 



Since his time several persons have gone from 

 England to different parts of Italy for the purpose of 

 making citrate of lime on the spots where the fruit 

 is produced, and considerable quantities have been 

 imported thence to Great Britain. As far back as 

 1808 an establishment of this sort was formed in 

 the island of Sicily : an ample account of it may be 

 found in Parkes' Chemical Essays. We are informed 

 there that " the country round Messina consists of 

 mountains of immense height rising one above 

 another, and thickly covered to the very top with 

 fruit-trees, chiefly olives and lemons, which render 

 this place the very best in the world for procuring 

 lemon juice." To this we may add that the oppor 



