644 Transactions of the American Institute. 



pupillometer. 

 By the aid of the apparatus invented liy M. Houdiu, any one can 

 nieti^ure the diameter of the pupil of his own eye. It consists of 

 a thin copper plate pierced with two holes, one of which is fixed 

 and the other movable. An index is attached to the plate, and at 

 the end of a small tube, for the purpose. of preventing light from 

 entering the eye except in one direction. On placing the instru- 

 ment to the eye, the holes ar& made to coincide, so as to form but 

 one impression upon the retina; but when changed from this posi- 

 tion, two pupilliuy disks, having the same diameter, form upon its 

 surface. This diameter is ascertained by making the two images 

 approach each other until they become tangential. The distance 

 between their centers is the diameter of the pupil; this is at once 

 indicated by the graduated index. 



HYBRIDIZING FRUITS. 



The Joicrnal of the Royal Horticultural Society contained some- 

 time since an account of experiments made by John Sandish, florist, 

 in hybridization, which were confined to greenhouse grapes and 

 fruits. He raised five hundred grape seedlings, and fruited four 

 hundred sorts. One of their most successful experiments was with 

 the Muscat of Alexandria, bearing an oval grape, very difiicult to 

 cultivate; and the Troveren, bearing a round grape, and a remark- 

 able free grower. The former was made the female parent. The 

 best result of many experiments was a large, early black grape, 

 oval in shape, and having the slightest possible taste of the Muscat. 

 The most remarkable case was a perfect miniature of the Muscat of 

 Alexandria, perfectly oval, with the strongest Muscat flavor, but in 

 size not larg-er than a red currant. 



He succeeded in obtaining peaches with nectarine flavor. The 

 nectarines, made the female plants, w^ere the Violctte Hative, Pit- 

 maston Orange, and the Stanwick, crossed with the Noblesse and 

 Barrington peaches. Although the Violette Hative nectarine had 

 a small flower, still, when crossed with the lai-ge flowering peaches, 

 eight out of twelve were large flowered; and out of fifteen kinds, 

 \ fruited in one summer, only one M'as a nectai'ine; the others were 

 all peaches, most of them with the nectarine flavor. 



A NEW GREENHOUSE. 



The new greenhouse constructed in England by Mr. Beard, is 

 composed of iron and glass, and rests on an iron wall-plate, which 



