Some Speculations on the Nature of Instinct. '25 \ 



the proper teinptiatnre. When wine is converted into 

 vinegar the alcohol entirely disappears, at least, as M. Chap- 

 tal observes, if the acidification is complete. But is alco- 

 hol in wine, the only princijj'e which is changed into vine- 

 gar? It has been said, tfiat the other matters contained 

 in the u-ine contribute to the formation of this acid. Sup- 

 posing this to be true, it is not less demonstrated that it is 

 essentially by its alcohol that wine is chansjed into vinegar. 

 What are the chemical chanires which this substance under- 

 goes in its conversion ? This is the object of inquiry. 



The phasnomena may be explained by referrina; them to 

 the action of the vegetable fermentable matter, and by at- 

 tributing them to the influence of the air. In the former 

 case, Rj. Vauquelin supposes that the fermentable matter 

 separates from the alcohol some of its carbon and hvdrogen 

 to form ammonia, and an oily matter, leavino- a nijre oxy- 

 genized alcohol, which is the vinegar. In the second case, 

 it is conceived by M. Thenard that the oxvgen of the at- 

 jTiosphere attracts the same principles from the alcohol, 

 whence results the formation of water and carbonic acid 

 gas, while the alcohol is converted into water. In both 

 these hypotheses the acidification of the alcohol is attributed 

 to the subtraction of a certain quantity of hydrogen and of 

 carbon from the alcohol, which renders the oxvgen predo- 

 minant in the acetic acid produced. The excess of this 

 oxygen is not very great, because the analysis of this acid 

 by the oxymuriate of i)otass did not afford MM.Gav Lus- 

 sac and Thenard more than 2-8G5 of oxygen in addition. 



This analysis evidently shows that a very small quantity 

 of oxygen is required to change alcohol into vinegar. It 

 shovv'S also, that vinegar is less ox\genized than any other 

 of the vegetable acids ; a very diflerent coticlusion from that 

 which places this product as the last term of vegetable oxy- 

 genation. From this analysis we can further conceive, how 

 vinegar may so easily be procured by such a variety of dif- 

 ferent means as have at different times been practised. 



XLV. Some Spectdations on the Nature of Instinct. By 

 Arthur Mower, Esq. 



JL HE philosophy of the human mind is a science which of 

 all others is the most backward, and one which by the li- 

 terary world in general seems to be the least regarded. 

 Whether it is that mankind are tired of metaphysical dis- 

 putes, and wdl no longer interest themselves in a theory 



one 



