530 ANNUAL OF SCIENTIFIC DISCOVERY. 







8. Ozone has no action upon either spirituous or lactic fermentation, or 

 upon the formation of mould. 



9. The white and yolk of egg, arterial blood, gall and urine of dogs, or 

 beef, in their fresh state, suffer no change after death, being moist and at 

 a temperature of from 80 to 90 F., if never brought into contact with 

 atmospheric air. 



10. In contact with pure oxygen, or with atmospheric air that has been 

 filtered through cotton, neither of the above substances is brought to putre- 

 faction. Still, the oxygen exerts a certain action, inasmuch as they all 

 change their appearance, and the white and yolk of egg, as well as the gall, 

 assume an acid reaction. The beginning of putrefaction, therefore, depends 

 upon some one or more agent which is commonly contained in atmospheric 

 air, and which is removed from it by cotton. 



11. Animal matter which is already in a state of putrefaction, or such 

 which has been exposed to the atmosphere for only twenty-four hours, and, 

 consequently, shows no outward signs of decomposition, induces putrefac- 

 tion in all the above-named substances without the aid of the atmosphere. 



12. The microscopic examination of the above-named animal substances 

 has shown that there exists no relation between their putrefaction and 

 between the development and growth of vibrios and other microscopic 



organisms. 



13. In view of all this, we must look to Liebig's chemical theory for a 

 solution of the process of putrefaction, with the reservation, however, that 

 the chemical ferment which induces the putrefaction acquires this property, 

 not by contact with oxygen merely, but with that ingredient of the atmos- 

 phere which is retained by cotton. Without this, that theory would not be 

 applicable for the fermentation of grape-juice. 



ON THE PRODUCTS OF THE DISTILLATION OF ORGANIC MATTERS. 



BY M. E. KOPP. 



The dry distillation of organic matters, whether vegetable or animal, from 

 the great variety of products to which it gives rise, constitutes one of the 

 most interesting operations of chemistry. The reactions to which these 

 products owe their origin are very complex, and some of them have been 

 but little studied, as indeed is the case Avith many of the substances formed. 

 If the body submitted to dry distillation could be maintained during the 

 operation under uniform conditions of desiccation, temperature, and pressure, 

 the reactions and the products would be much more simple. If, for example, 

 wood be heated very slowly in a close vessel, first to one hundred degrees 

 Centigrade, then to two hundred degrees, three hundred degrees, and s.o on, 

 there is at first disengaged almost pure water, then impure, strong acetic 

 acid, and afterwards a mixture of acetone and acetate of methylene; the 

 maximum of charcoal is left as residue, and the least amount of tar and gas 

 is produced, the latter consisting only of carbonic acid and carburetted 

 hydrogen. 



In practice, however, when wood is distilled in cylinders of iron heated 

 from the outside, the heat only penetrates to the interior gradually. The 

 outside layers are therefore the first decomposed; they at first lose water, 

 then furnish pyroligneous acid and wood-spirit, at the same time giving off 

 carbonic acid and a little carburetted hydrogen. The inner layers in turn are 

 similarly decomposed"; but the products as they are given off are brought 



