Retrospective Criticisin. 4-97 



England. — I am also curious to know what progress the cultivation of 

 mulberry trees and silkworms is making in England. In Lonibardy there 

 has been lately introduced a new species of mulberry, which is said to be 

 originally from the Philippine Islands. The leaf is 9 in. long, and Gin. 

 broad ; it is sometimes called il/orus cucuUata, from the leaf itself being 

 formed like a cartoccio [papers used by grocers], and sometimes Morus 

 multicaulis, from the number of stems which rise from one root. It 

 increases more vigorously than any other species, the shoots of one year's 

 growth attaining the height of 7 ft. As plants which increase very rapidly 

 are scarcely ever injured in a damp and humid soil, I am of opinion that 

 this would be the sjiecies of mulberry most suitable to England : the colds 

 of England would not injiu'e them ; as, when at Turin, they stood in the win- 

 ter of 1829-30, a cold of 16° Reaum. (7° Fahr.) This species of mul- 

 berry is especially adapted for forming hedges. It yields, in a very short 

 time, a greater quantity of leaves than any other species; it scarcely ever 

 fruits, but is pretty easily propagated by means of cuttings, of which, if 

 you desire any, let me know, for 1 shall have much pleasure in serving you. 

 [We thank our correspondent, but have seen them at Messrs. Loddiges.] 



The silk harvest was very scanty this year in Lombardy, on account of 

 the lasting rains which fell in the spring, and made the leaves of the mul- 

 berry trees wither. On the contrary, the olives yielded an extraordinarily 

 abundant crop. While I am writing, I have received an account from 

 I^ario, that the gathering of the olives, which commenced in the beginning 

 of December, is now scarcely finished. Well-cultivated olive grounds will 

 produce, for every perch (one fifth of an acre), not less than fifteen bushels 

 of olives, and these, at the mill, will yield 105 pounds avoirdupois of oil, 

 which is worth no less than 30 soldi (about a shilling) per pound. The 

 cause, in my opinion, of the unusual fertility of the olives this year was 

 the same that occasioned so much havoc to the silkworms ; I mean, the 

 abundant and frequent rains which fell after June, that is, after the flower- 

 ing of the olives. 



Cobbeft's Indinji Corn, and a Kind grown In Lombardy, — I have read in 

 your Magazine, and also in the Political Register of Mr. Cobbett, of a sort 

 of Indian corn, named after the celebrated politician who introduced it 

 first into England. Two years ago, a variety or species, originally from 

 California, was introduced into Lombard}', which is very early, and pro- 

 duces two ears on each stalk, each containing 700 or 800 grains, small, 

 but more transparent than I have ever seen in any other kind of maize. 

 In the mill it makes very little bran, and yields a great deal of flour, which 

 is said to have more flavour than the other sorts. Its distinctive charac- 

 ters were thus defined by Signor Bonafous of Turin : — " Zea, foliis hirtis 

 et dependentibus ; spiculis masculis sessilibus, diandris triandrisve : antheris 

 subaureis." Can this variety or species be the same as Cobbett's corn ? 

 If it is not, I will send you the seeds of it, that you may distribute them 

 to different cultivators in England, from whom I will receive, with grati- 

 tude, some seeds of Cobbett's corn. 



Mr. Gauen^s Alode of I/eating Air by Lenses, for j^romoting the Processes 

 of Vegetation. (Vol. III. p. 10.) — I was much interested in Mr. Gauen's 

 idea (Vol. III. p. 10.) of heating with lenses, mounted on a suitable 

 frame, which should continually present to the sun immense masses of 

 air, or, as you propose, water. The late professor of natural philosophy 

 (fisica), in the Lyceum of S. Alessandro, in Milan, Signor Antonio Cri- 

 velli, had contrived a cone or trunk of brass, or I should rather say a cone 

 terminated in a calotta [?], with which he so concentrated the rays of the 

 sun, as to carbonise a diamond. By varying the relation between the 

 height and the length of the cones, he varied also the distance of the focus ? 

 so that he could inflame an object at the distance of 40 or 50 ft. BufFon, 

 having constructed a system of burning glasses, supposed that it was the same 

 , Vol. VIII. — No. 30. kk 



