^H§ Intelligence a)id Miscellaneous Articles. 



difference between my left and right, from long habit of using mi- 

 croscopes, still the general result is similar in each, and I think such 

 as must be detected by other persons. 



I made a small square bounded by narrow lines on a sheet of paper, 

 and closing my left eye, I observed that the image was double, the 

 false one being raised, and to the left of the true the interval filled 

 up with a pale reddish-brown spectrum, most intense near the true 

 image ; the breadth of the interval about 0"03 inch. With my right 

 eye closed, the image was, as I expected, to the right and above (in 

 both instances towards the brow and nose), and the interval simi- 

 larly tinged, but fainter, and 0*025 inch wide. 



I then took a slip of card, and made with a pen-knife a fine slit in 

 it, and looked through it held horizontally at the square ; the upper 

 false image was no longer visible, the upper and lower sides of the 

 square clearly defined, but the lateral sides were unchanged ; on 

 holding the slit vertically, the lateral false images disappeared and 

 the upper and lower returned. Similar appearances occurred with 

 the other eye. 



I now took a card and made two fine pin-holes exactly in the 

 positions of the centres of my pupils, and I found that I saw the 

 true image as coi'rectly as I had ever done in my life ; in fact, it sup- 

 plied the place of a pair of spectacles ; the square, of course, being 

 seen under a greater angle, apjjearing magnified. By making the 

 pin-hole larger or smaller, the focal distance, if I may use the ex- 

 pression, increased or diminished proportionably. I beg further to 

 remark, that in the sunshine I can read small print at the natural 

 focal distance ; it is only in fainter light that the double image and 

 confusion of letters occur. Now a flattening of the cornea won't 

 explain all this : it seems to have a more intimate connexion with 

 some want of contractility engendered in old age in the iris. I am 

 curious to obtain an explanation, and send this notice to you for the 

 purpose of eliciting one. 



Truly yours, 



R. T. Cranmore. 



P.S. I have since observed that wire-gauze, the wire being very 

 fine, and the meshes about -J^th of an inch in diameter, when worn 

 close to the eye, enables me to read small print with tolerable faci- 

 lity at a distance of five or six inches ; when the meshes are closer, 

 I can see the most minute objects with remarkable distinctness. 



Brompton, May 4, 1850. R. T. C. 



ON THE EXISTENCE OF IODINE IN FRESHWATER PLANTS. 

 BY M. AD. CHATIN. 



In verifying the fact stated by Muller (Lindley's Vegetable King- 

 dom), of the existence of iodine in a cress of unknown origin, the 

 author has ascertained — 



That iodine exists in freshwater cresses, that it is not peculiar to 

 this species, nor general with respect to plants of the family of the 

 Cruciferse ; 



That iodine does not exist, or at any rate cannot be discovered in 

 terrestrial plants, whereas it exists in all aquatic plants ; 



