^^I've already accepted it was my mistake, please don't drag it further.
Now as for Hawan, let me tell you that is also has a scientific importance. This is an age-old Hindu ritual in which offerings of ghee, googol,  sugar and other saamaagri are offered into the sacred fire to the  accompaniment of Sanskrit mantras. [FONT=Verdana, Arial, Helvetica, sans-serif][FONT=Verdana, Arial, Helvetica, sans-serif][FONT=Verdana, Arial, Helvetica, sans-serif][FONT=Verdana, Arial, Helvetica, sans-serif]It is a  rare combination                      of accupressure, touch healing, meditation,  psychiatry, knowledge                      and wisdom.[/FONT] [/FONT][FONT=Verdana, Arial, Helvetica, sans-serif]Havan                      is a scientific procedure, which is associated with  the science                      of mind and soul. This science was realised by our  great rishi-munis                      or seer scientists in Vedic times, through their  mind power. 
[/FONT][/FONT][/FONT]Yajurveda says that four types of things mainly used to prepare  offerings for a Havan- 1. Sweet Like honey, jaggery, raw sugar etc., 2.  Antibiotic herbs like gyol, etc., 3. Nutrition like pure ghee, dry  fruits etc., 4. Fragrant materials like elaichi (cardamom) dried petals  flowers etc.
Scientific experiments have proven that havan destroys harmful bacteria  in the atmosphere. A scientist named Tautilk proved that a patient  stricken with typhoid disease can be freed of this scourge if he is  exposed to the smoke of havan for half hour.  
With the development of the modern science we are getting more dependent  on synthetic chemicals to kill bacteria or remove pollution other than  the use of natural sources like medicinal plants or energy like Sun. In  our ancient days people used the natural sources to fight the bacteria  and pollution.
If you want to read in much detail, it's the complete answer to your statements-
American Chronicle | Smoke of medicinal plants can kill harmful bacteria.
And don't call it a copy-paste now, I had to do it in order to clear your doubts. If I am linking something informative and as a proof, there should be no problem with that.
And Now please don't write anything ambiguous about this sacred ritual[FONT=Verdana, Arial, Helvetica, sans-serif].[FONT=Verdana, Arial, Helvetica, sans-serif][FONT=Verdana, Arial, Helvetica, sans-serif]
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