Part of David's interest in incense and precious oils had started on a trip to Dubai where he had discovered frankincense for sale at approximately £4 a pound which destroyed some of the myth about this material. Part of the religious culture of that region is the burning of oud under the cloak to fragrance the material. Oud is priced at $50 for a few drops and is therefore a very precious oil. The Japanese equivalent of Oud is Aloes wood, which can be just as precious.

Incense is sold in Japan in shops similar to Tobacco shops and is available in many different varieties for imparting different stimuli suck as relaxing, sleeping and waking. The blend of oils used is a carefully guarded secret, which is passed down from generation to generation. David then went on to explain how the brain picks up the scent from the incense and how the brain waves formed are similar to those seen when narcotic drugs or pheromones are used. The mechanical effects formed can be similar to those seen for stimulating, calming, and sexual stimuli.

The recorded use of incense predates its use in Japan and examples of its use can be seen on Queen Neffertiti's tomb. In this case the incense was probably based on cinnamon and was buried with the Queen to accompany her in the after-life. Incense is also mentioned in connection with the Queen of Sheba in the Court of King Solomon and the history of the "spice trains" which dates back to approximately 1000 BC.

As well as reference to "gold, frankincense and myrrh" in the bible, a 15th century French book contains details of Arabians collecting incense and there are details of Marco Polo's journey across Africa via Ethiopia, which in those days was seen as brigand and bandit territory. Due to current conflicts it is still an unstable part of the world.

David then went on to explain how the spice trains ran from Iran to China via the ancient trading post of Bactria, crossing over the Great mountain range where the height above sea level ranges to greater than 12,000 feet, higher than Mount Blanc.

The spices and oils brought via this route include Sweet Myrrh, Clove from Zanzibar, Cedar, Cinnamon, Mussel (a spice for which David can find no modern equivalent), scented Opopanax, Spikenard, Storax, Hinoki, Ambergris, Haisokoh, Patchouli, Frankincense and Myrrh.

The route from Iran to the "Jade Gate", the entrance to China, where spices enter the country was 6000-7000 miles in length and details of the journey have been found in a poem dating back to 800 AD.

David then went on to the part of the lecture, which he titled "What I did on my holidays". He was fortunate enough to spend a week working in a factory in Japan which produced incense and where he met the Kodo master and the chemists involved in the production of incense...

The process starts by the careful chipping and grinding of the Aloes wood, without any friction which would affect the chemistry of the wood once it is burnt. Then dye and nitrate, to aid the burning, are added. These are then mixed cold with essential oils and water to form a paste which is subsequently extruded (sometimes using a computer controlled process), manually cut to length, which is a very difficult process, and then allowed to dry, using air, sometimes without wind.

The burning of the incense is carried out with much ceremony, similar to that used in the tea ceremony. The bowl used for the burning is usually highly decorated and may be passed down from generation to generation. The bowl is filled with unperfumed rice-ash to which is added decorated charcoal, which is subsequently lit. The charcoal is covered with ash, using chopsticks, and this is formed into a "mountain" and the surface is carefully decorated. On top of the mountain is placed a mica plate. The aloes wood is then brought in with great ceremony and placed on top of the mica plate. The gentle heat from the ash activates the wood.

David explained that Kodo is one of the lessons learnt by "geisha girls" which also include Zen, the Tea ceremony, flower arranging, singing, calligraphy and incense burning. The burning of incense is said to purify both mind and body and provide a companion in the mist of solitude. Ritualistic "games" can also be played with the burning of incense in which a story, such as one of a journey, can be told.

This lecture by David gave a fascinating insight into the history and culture of something that to the majority of the audience is associated with hippie culture and a means of fragrancing the home.