



Miscellaneous Intelligence. 13 



o 



In connexion with this subject, I may mention another phenomenon 

 equally curious and perplexing, to be observed with these same patterns, v 

 The blue spot, when viewed indirectly, always appears lighter than it 

 really is ; and when the eye turns full upon it, it resumes its proper 

 color with a kind of start : the red spot again appears much darker by 

 indirect vision, and becomes as suddenly light again when (he eye is 

 directed straight towards it. There is no doubt that these changes of 

 tint serve to heighten the illusion of apparent motion when the eye is 

 allowed to wander over the different parts of a complicated pattern. 

 This phenomenon may perhaps be explained by the fact of the sight 

 being most perfect in the axis of vision, or, as Sir David Brewster has 

 expressed it, " the eye has the power of seeing objects with perfect dis- 

 tinctness only when it is directed straight upon them, so that all objects 

 seen indirectly are seen indistinctly ;" and it may be supposed that im- 

 pressions received in those parts of the retina used in oblique vision 

 are, as it were, diffused. Thus the red and blue spots, when viewed 

 indirectly, appear tinged with the prevailing color of the ground of the 

 pattern, — the red spot becoming darker by the influence of the blue 

 round it, and the blue spot lighter by the vicinity of the red ; for it is 

 remarkable that this illusion is not produced with single colors, only 

 with spots of one color surrounded by a field of the other. 



In concluding these observations, I have only to add, that there can- 

 pot be much doubt of the correctness of the view which ascribes the 

 illusory appearance of motion to the change of tint at the edges of the 

 figures. These are matters of fact : but whether the theories offered 

 in explanation of the facts are correct are not, I must leave to more 

 competent observers to determine. 



9. The Tea Plantations in the N. W. Provinces of India, and the 

 Culture of American Cotton in India, (Jameson's Jour., July, 1848, 

 vol. xlv, p. 191.) — In the Journal of the Agri-Horticultural Society of 

 India, the leading article, which is also the longest and most valuable, 

 is descriptive of the tea plantations in Kumaon and Gurhwal, and of 

 the mode of manufacturing black and green teas. It is from the pen 

 of Dr. Jameson, superintendent of the Botanic Gardens of Upper India, 

 and is drawn up in the shape of a report to the Lieutenant-Governor of 

 the N.W. Provinces. A clearly-detailed and well-arranged paper, we 



doubt not it will be perused with pleasure by all who take an interest 

 io so important a culture. Apart from the satisfactory view it affords 

 °f what has hitherto been effected, it gives much useful information on 

 many other points, and is therefore likely to prove a valuable guide to 

 those who may hereafter be induced to carry out on an extended scale, 

 the work in which the government are now acting the part of pioneers. 

 We cannot undertake to give an a! tract of this report, further than to 

 mention, that the nurseries in Dr. Jameson's charge occupy altogether 

 162 acres, all under culture. Of these, rather wore than 30 acres 

 were added during last year. That, in addition to the plants reserved 

 for manufacturing purposes, these nurseries have lately yielded twoand 

 a-half lac of seedlings, ready for transplanting at the time the report 

 was furnished, and of which the greater part has been appropriated for 

 the additional land selected in the Dherah Dhoom A crore and up- 

 wards of seeds have again been sown, which will give a large additional 



