126 TRANSACTIONS OF THE PROVINCIAI, &C. 



think that they will be found chiefly to be such as are connected 

 with the numerous manufacturing processes carried on in the towns, 

 many of which are of a very noxious character. The rate of mor- 

 tality in the city of Worcester in 1821, was 1 in 48, which of course 

 will lessen the rate of mortality in the rest of the county, reducing 

 it in fact from 1 in 53, to about 1 in 56. But the glove and china 

 manufactures are by no means so prejudicial as those followed in 

 some of the other towns, and were we to abstract the inhabitants of 

 these towns from the general mass of the population of the county, 

 we should find that the rate of mortality would fall materially lower, 

 and might probably not exceed that of the agricultural parishes of 

 the Landsend. From an average of 10 years, namely, from 1813, 

 to 1822 inclusive, the proportionate mortality of the City of Bris- 

 tol appears to be still greater than that of Worcester, the ratio 

 amounting to 1 in 45. Many curious facts of individual lon- 

 gevity will be found in Dr. Forbes's paper, which will derive 

 additional interest by comparison with those furnished by Dr. 

 Hastings, in his Illustrations of the Natural History of Worces- 

 tershire. For these and for a variety of information respecting 

 the customs, manners, pursuits, habits of life, and general 

 condition of the inhabitants, and for instructive details of the 

 operations and effects of mining, and other occupations in which 

 the population is employed, we must refer to the paper itself. 

 From what we have said our readers will be at no loss to 

 gather the opinion we have formed of Dr. Forbes's Essay. It is 

 indeed a production of very superior cast, and evinces a labour and 

 patience of research which is rarely equalled. The paper of Drs. 

 Carrick and Symonds is also one of great merit, though less ample 

 in its details. That of Mr. Watson possesses much local interest, 

 and affords a good deal of information respecting the Natural 

 History of the neighbourhood. We feel that our task has been 

 very imperfectly fulfilled. The numerous and important subjects 

 brought before us scarcely admitting of condensation and requir- 

 ing a much more extended account than we could possibly afford 

 space to give ; we trust, however, that we have said sufficient to 

 induce our readers to consult the original articles for themselves, 

 and we can assure them that if they will take up the subject and 

 pursue like investigations in their several localities, that not only 

 will they derive a pure gratification in the employment, but will also 

 be engaged in a work which promises more for the benefit of their 

 fellow creatures, than most others to which they could turn their 

 attention. E. M. L. 



Optical Experiment. — Place on white paper, a circular piece of blue silk, about 

 four inches diameter, in the sunshine — place on this a circular piece of yellow, 

 three inches in diameter — on this a circle of pink, two inches diameter — on this a 

 circle of green, one inch diameter — on this a circle of indigo, half an inch diameter ; 

 making a small speck with ink in the centre — look on this central point steadily 

 for a minute, and then closing your eyes and applying your hand at about one inch 

 distance before them, so as to prevent too much light from passing through the 

 eyelids, you will see the most beautiful circles of colours the imagination can con- 

 ceive, not only different from the colours of the silks above mentioned, but the 

 colours will be perpetually changing in Kaleidoscopic variety as long as they exist. 



