256 ANNUAL OP SCIENTIFIC DISCOVERT. 



be allowed to enter the room of the patient or hospital. As a further eluci- 

 dation of this subject, the following more strictly chemical remarks are 

 offered. 



The origin of these salts is connected with the production of acids, as well 

 as alcohol, in fermenting vats. When the wort is subjected to heat in the 

 still, acetic, butyric, and other acids rise with the vapor of alcohol, and pass 

 into the condenser, now most commonly made of copper, with masses of 

 solder containing lead. At the instant of condensation, these acids exert a 

 power of corrosion on the metals quite unsuspected, and the salts formed 

 dissolve in the spirit. Where condensers of pure tin are used, no copper 

 salt is found, and a little tin salt takes its place. 



With^he vapor of dilute alcohol some vesicular vapor of the wort is car- 

 ried forward, and the dextrine which can be found in the spirit; another 

 portion of soluble organic matter is abstracted from the wood of the cask, 

 and this is often tannic acid. In the subsequent, chemical changes, these 

 organic compounds unite with the salts, and fall in the form of a sub-granu- 

 lar, dark matter, seen in colorless spirits of all kinds. In detecting the 

 metals held in solution, the extract obtained, after evaporating the spirit, 

 must be destroyed, as usual in toxicological testing, and an acid solution of 

 the oxide obtained; or the extract may at once be mixed with carbonate of 

 soda, and the metal reduced by the blowpipe flame. When the deposit is 

 the subject of trial, the metal or metals appear on fluxing with carbonate 

 of soda, in the inner flame produced by the blowpipe, on charcoal. 



ON CATALYSIS; OR, ON THE CHEMICAL AGENTS OF DISEASE IN 



THE LIVING BODY. 



The following is an abstract of a lecture recently delivered on the above 

 subject, by M. Claude Bernard, Professor of General Physiology of the 

 Faculty of Sciences, Paris : 



We have hitherto maintained that idiosyncrasies ought to be referred to 

 certain peculiar organic predispositions, which, far from introducing physi- 

 ological laws of an entirely novel character into the economy, are the natural 

 result of the properties enjoyed by the nervous system. 



It is also known that animals debilitated by want of proper nourishment 

 submit less readily to the agency of certain poisons than others in a vigorous 

 state of health; but it has been questioned whether similar modifications are 

 due to nervous influence, and whether the diminished activity of the absorb- 

 ent powers is not sufficient to explain them. In order to settle the question 

 at once, I injected an aqueous solution of woorara into the veins of two 

 rabbits, one of whom had been previously fasting, while the other was duly 

 fed; in this manner, absorption was entirely dispensed with, the poison 

 being at once conveyed into the blood. The result was such as might have 

 been expected. To poison the fasting animal a dose larger by one-third was 

 required than had been found sufficient to destroy the other. It is, therefore, 

 perfectly clear that all this class of phenomena must be entirely referred to 

 the agency of the nervous system. 



But, while the animal is in some measure preserved from the noxious 

 influence of certain poisons through the rapids-increasing debility of its 

 nervous system, it becomes obnoxious to the action of morbid influences of 

 a totally different character. It even appears to me that in our nosological 



