APPENDIX. 167 



any mention of these trees. Doubtless the Arabians 

 had already naturalized them in Africa and Spain, 

 where the temperature favored so much their growth. 

 Doubtless Liguria is the part of Italy where the cul- 

 ture of the Agrumi has made most progress. We 

 have certain testimony to this in the work of a doc- 

 tor of medicine of Mantua, writing near the middle 

 of the thirteenth century. He says : 



" The lemon is one of the species of citrine 

 apples, which are four in number. First, citron. 

 Secondly, orange (citrangulum), of which we have 

 spoken before. Thirdly, the lemon. Fourthly, 

 the fruit vulgarly called lima. These four species 

 are very well known, principally in Liguria. The 

 lemon is a handsome fruit, of fine odor. Its form 

 is more oblong than that of the orange, and, like 

 the orange, it is full of a sharp acid juice, very 

 proper for seasoning meats. They make of its 

 flowers odoriferous waters, fit for the use of the 

 luxurious. 



* * The trees of these four species are very similar, 

 and all are thorned. The leaves of the citron and 

 lime are larger and less deeply colored than those 

 of the orange or lemon. The lemon is composed 

 of four different substances, as well as the citron, 

 lime, and orange. It has an outer skin, not as deep 

 in color as that of the orange, but which has more of 

 the white. It is hot and biting ; thus it shows its 

 bitter taste. The second skin or pith, between the 

 outer skin and the juice, is white, cold, and difficult 



