142 Analysis of Scientijic Books. 



now and then an interruption, for reasons before assigned, by the 

 transient croak of the raven, the screaming- of the jay and the 

 swift, or the pert chattering of the daw. The nightingale, un- 

 wearied by the vocal exertions of the night, withdraws not proudly 

 by day from his inferiors in song, but joins them in the general 

 harmony. The thrush is wisely placed on the summit of some 

 lofty tree, that its loud and piercing notes may be softened by dis- 

 tance before they reach the ear, while the mellow black-bird seeks 

 the inferior branches. Should the sun, having been eclipsed with 

 a cloud, shine forth with fresh effulgence, how frequently we see 

 the aoidfinch perch on some blossomed bough, and hear his song 

 poured forth in a strain peculiarly energetic, much more sonorous 

 and lively now than at any other time, while the sun, full shining 

 on his beautiful plumes, displays his golden wings and crimson 

 crest to charming advantage. The notes of the cuckoo blend 

 with this cheering concert in a perfectly pleasing manner, and for 

 a short time are highly grateful to the ear ; but sweet as this sin- 

 gular song is, it would tire by its uniformity, were it not given in 

 CO transient a manner. At length evening advances, the per- 

 formers gradually retire, and the concert softly dies away. The 

 sun is seen no more. The robin again sends up his twilight song, 

 till the still more serene hour of night sets him to the bower to 

 rest. And now to close the scene in full and perfect harmony, no 

 sooner is the voice of the robin hushed, and night again spreads a 

 gloom over the horizon, dian the owl sends forth his slow and 

 solemn tones. They are more than plaintive and less than melan- 

 choly, and tend to inspire the imagination with a train of contem- 

 plations well adapted to the serious hour. Thus we see that birds, 

 the subject of my present inquiry, bear no inconsiderable share in 

 harmonizing some of the most beautiful and interesting scenes in 

 nature."— Pp. 35-38. 



3. On the Nature of the Acid and Saline Matters usually existing 

 171 the Stomachs of Animals. By William Prout, M.D., F.R.S. 

 The object of Dr. Front's paper is to investigate the nature of 

 the acid and saline matters usually existing in the stomachs of 

 animals ; he introduces the subject with some remarks upon the 

 previous opinions of chemists and physiologists, in relation to the 

 nature. and sources of the acid and salts in question, and then 

 proceeds to the detail of the experiments which led him to conclude 

 that the free acid in the stomach is muriatic acid, and that the 

 salts are the alkaline muriates. We wish our chemical readers to 

 determine for themselves how far these points are satisfactorily 

 proved, and therefore lay before them the details in Dr. Prout's 

 own words. 



" The contents of the stomach of a rabbit fed on its natural food, 



