512 



The present paper purports to be the sequel of a work, already 

 published by the author, on the subject of the education of animals. 

 It is the first part only of the paper which is here presented, and 

 contains j^reliniinary observations on the nature of the inquiries 

 which the author proposes to enter into in the subsequent parts. It 

 is divided into three chapters ; the first comprising some general 

 remarks on the objects to be attained in the education of animals, 

 and some criticisms on the opinions of preceding writers relating to 

 the subject ; the second treating principally of Instinct and its cha- 

 racteristic features, as contrasted with Intelligence and Reason ; 

 and the third entering into various metaphysical disquisitions on the 

 nature and peculiar sphere of action of the different intellectual 

 faculties, both those which are common to man and the lower 

 animals, and those which are peculiar to the former. 



June 13, 1844. 



The MARQUIS OF NORTHAMPTON, President, in the Chair. 



1. " On the Action of the Sun's Rays on Lithic Acid." By John 

 Davy, M.D., F.R.S. Lond. and Edinb. 



The author, after adverting to the composition of guano, and re- 

 marking that its nitrogenous part differs from the urine of the sea- 

 fowl, from which it is derived, chiefly in containing little or no 

 lithate of ammonia, but a large proportion of the oxalate, describes 

 an experiment made for the purpose of determining whether the 

 oxalic acid existing in guano may not be formed from the lithic 

 acid of the urine, in consequence of the operation of the sun's rays. 

 The result of a comparative trial made with the urine of the white- 

 headed Sea-Eagle, in one instance kept in darkness, in the other 

 exposed to bright sunshine for many successive days, afforded an 

 answer in the affirmative. Whilst the urine of the Sea-Eagle, con- 

 sisting chiefly of lithate of ammonia, kept in the dark, underwent 

 no change, that exposed to light was materially changed, most of 

 the lithate of ammonia had disappeared, its place was supplied by 

 oxalate of ammonia, the peculiar odour of guano was acquired, and 

 in part its brownish hue. 



From considering the composition of the lithic and oxalic acids^ 

 the author infers, that in the conversion of the one into the other, 

 oxygen is absorbed ; and, in confirmation, he mentions that although 

 no change takes place when moist lithate of ammonia is exposed 

 alone to a temperature of about 212°, it is otherwise if so treated 

 when mixed with black oxide of manganese, in which case oxalate 

 of ammonia is formed, and also some brown colouring matter, not 

 unlike that of guano ; and this colouring matter, he supposes, may 

 appropriate to itself the excess of carbon and hydrogen, that is, 

 such proportions of these substances in the lithic acid as are more 

 than those required to form oxalic acid and ammonia. 



