Biologists had long harboured a hunch that the extinct volcano of Mount Bosavi in the jungles of Papua New Guinea could contain a treasure trove of undiscovered species. Its high crater walls meant that animals contained within them have evolved in isolation for thousands of years. Scientists had never been inside and so an expedition was planned involving a team of biologists and naturalists, but the TV crew, who would film it for a documentary series, outnumbered them all. The producer was charged with sorting out the logistics of the mission. He and a researcher flew by helicopter to the nearest village, a 4-day trek from the volcano, and sought the permission of local people to film there. Concerned not to consume the local resources, they also arranged for sweet potatoes to be planted, reducing the quantities of rice and canned food that would need to be flown in. After six months, the harvested yield would sustain expedition members during their time there. A base camp was established near the village and eventually the rest of the team arrived. Local tribespeople were employed, who, though they had some knowledge of the crater, had always judged it too inaccessible to visit regularly. An advance party headed out to locate somewhere a helicopter could land. In charge was a skilled climbing professional who, with the help of local hunters, would scale the mountainside and enter the crater itself. Once inside, they found an area where a helicopter could land.  The time was then right for the others to head for the crater. Flying in, they were greeted by vegetation dripping with diverse life-forms. The volcano teemed with so much life that it took just 30 seconds to discover a new species of frog, and even then they almost squashed it. By the time they re-emerged from the crater this would be just one of 16 frog species catalogued for the first time, including one with long pointed teeth more akin to a snake s. Despite being hot, dirty and sweating for much of the time, the naturalists were ecstatic. The jungle within the crater walls revealed stick insects the length of a human forearm or huge fat-lipped fish that looked as if they d swallowed an octopus. Butterflies, some with dimensions closer to those of a paperback, fluttered everywhere, many of which were already documented. Most biologists consider it an achievement to name one new species, but in rainforests as remote as this the discoveries seemed endless. They also had the daunting task of assigning names to their finds. One caterpillar awaiting cataloguing provided a source of amusement. The hairy creature bore more than a passing resemblance to the eyebrows of a political figure and could well provide inspiration for its ultimate labelling. One of the team s naturalists, Steve Backshall, chanced upon a tree kangaroo as he combed the areas alongside the streams for unfamiliar creatures. Tree kangaroos are notoriously wary of people, but this one was unfazed by the team s presence, confirming suspicions that the crater walls had effectively cut off the animals living within, allowing them to remain innocent of the danger humans could represent. The most exciting discovery was of a giant rat recorded rummaging around on the forest floor, after being captured by what s known in the trade as a camera trap. Members of the team were awed by its size and suspected it could be a new species but needed to see the animal in the flesh to be sure. Trackers caught a live specimen which measured 82 cm from nose to tail and weighed around 1.5 kilos. After a fortnight within Bosavi s crater, some of the group visited the island of New Britain, several hundred kilometres to the east of New Guinea. The volcano there is active and their goal was to observe its activity, and chart the caves there, believed to be the deepest in the southern hemisphere, and a likely location for further incredible discoveries. Sudden spectacular volcanic activity, however, forced them to make a premature departure, bringing this remarkable expedition to a close.

I want to talk to you today about a spice which is not very well known outside its home territory, and that is mastic. Mastic is a resinous substance which comes from a tree of the pistachio nut family and it is one of Europe’s oldest spices. In fact, in its heyday it was considered so precious that armies quite literally fought over the islands where it was grown so that their masters would have the right to control its cultivation and sale.

Let’s take a look first at how mastic is produced. The mastic tree itself resembles an olive to the untrained eye but is not quite as large. In a process which is rather similar to the collection of rubber, growers cut the bark of the tree so that the tree then has to exude a sticky sap or resin to heal the wound, and this sap is mastic. The sap needs to harden in order to be of any use and strangely this only happens in the Mediterranean area. Efforts have been made in the past to transplant and cultivate the tree in other parts of the world, but so far without success.

The resin is then removed from the tree and, because it’s so precious, people even pick up the dirt under the tree and ensure that every last tiny bit of mastic is harvested. The growers try to pick out any grit which might have become embedded in the mastic gum. They just use simple pins to do this; unusually for nowadays, there are no mechanical aids or gadgets to speed up the process. Everything is still done in the traditional, labour-intensive way, by hand. If you examine a small piece of mastic it will look like a white crystal, similar to sea salt. Poets have even mentioned mastic in their work, alluding to it rather romantically as‘silver tears’, suggesting again how much it’s valued.

Having harvested and cleaned the crystals, the growers often take the mastic from their trees, except for a small amount which they keep for their personal use, to a local cooperative, which contacts various commercial buyers and negotiates a decent price for the growers.

Now, what is mastic actually used for? In fact, its use can be traced back thousands of years. Archaeologists have found small lumps of mastic with the imprint of juvenile human teeth, suggesting that the earliest use of mastic was as a chewing gum for young people, something which still occurs today.

Nowadays it’s also used as a flavouring in sweet things like biscuits and to great effect in ice cream. Its value here is that it also provides a stickier texture, which means that it takes longer to soften, a useful quality in the hot Mediterranean summers. Mastic can also be used to flavour liquids. For example, in some rural areas, small fires are lit and a few grains of mastic dropped on the hot charcoal. Then pots are inverted on top so the clay picks up the flavour of the smoke and the mastic. Chilled water is then poured in, and when this is drunk it tastes very subtly of mastic.

Apart from its culinary uses, some mastic is also sold for other purposes. It can be used in shampoo, toothpaste and, indeed, for certain stomach ailments. In fact, it’s this area that mastic producers are now looking towards to provide a wider use for their produce, now that natural herbs and spices are being investigated to provide the medical products of the future.