CHElSnCAL SCIENCE. 199 



persons without warning as to their application. The best plan 

 of disinfection should, thei-efore, be definitely settled, and its 

 adoption made uniform. Disinfectants should always supplement 

 each other, so as to pervade the whole mass on the meeting 

 of the contents of various sewers. The opposite, however, is 

 now taking place in London. Oxydizing disinfectants are by 

 far the best known and most used, as they appeal directly to 

 popular prejudice by destroying foul odors; whilst antiseptics 

 have little or no action on these gases. This fallacious mode of 

 estimating relative value is an injustice to antiseptics. In prac- 

 tical work, oxydizing disinfectants are always very inadequate, 

 except for a short time after application. At other times the oxy- 

 dizing agent has more noxious material than it can conquer ; and, 

 beinp^ governed in its combinations by definite laws of chemical 

 affinity, the sulphuretted and carburetted hydrogen, the nitrogen 

 and phosphorus basis, and other vapors, all have to be burnt up 

 before the oxydizing agent can touch the germs of infection, 

 whilst the renewal of the gases of putrefaction will constantly 

 shield the infectious matter from destruction. Oxydizing disin- 

 fectants destroy infectant substances ; antiseptics act by destroy- 

 ing its activity. Of all antiseptics, tar and acids are most 

 powerful ; and, of these, carbolic acid. By the latter, embryotic 

 life is rendered well nigh imjiossible, and all minute forms of 

 animal life perish inevitably. If the infectious matter of cholera 

 possesses, as is now almost universally admitted, organic vi- 

 tality, it will be destroyed beyond revival when brought into 

 contact with this vapor. The addition of permanganate of 

 potash to water will destroy the cholera virus. The oxydizing 

 powers of this agent, although very energetic on dead organic 

 matter, are successfully resisted by living organisms. The sci- 

 entific prosecution of accurate experiments and observations iu 

 reference to the cholera, similar to those in respect of the cattle 

 phxgue, are highly important, as the third report of the commis- 

 sioners on the latter subject has given us more insight into that 

 pestilence than we possess of any human zymotic disease, and 

 there is no reason why a similar plan should not be carried out in 

 this instance. — W. Ckookes, in Header. 



The Hastings Prize Essay on this subject, by Dr. Thomas Her- 

 bert Baker, is pulilished in the number of the "British Medical 

 Journal " for January 6, 1866. The following is a summary of 

 the author's conclusions : — 



1. For the sick-room, free ventilation, when it can be secured, 

 together with an even temperature, is all that can be required. 



2. For raj^id deodorization and disinfection, chlorine is the most 

 effective agent known, 



3. For steady and continuous effect, ozone is the best agent 

 known. 



4. In the absence of ozone, iodine exposed, in the solid form, 

 to the air is the best. 



5. For the deodorization and disinfection of fluid and semi- 

 fluid substances undergoing decomposition, iodine is best. 



6. For the deodorization and disinfection of solid bodies that 



