Since ancient times, the Oleo-resin collected from Sal tree is widely used for its healing properties and mood lifting fragrance, explainsDr. Pradosh Samal 

The road towards Daringbadi enters a dense forest area after around 12 km drive from Mandasaru, called the silent valley of Phulbani district located in the heart of Odisha. The tropical forest gets denser on both sides of the road, predominantly covered by tall Salua or Sal trees. That means, one has arrived at the famous Salua forest of the region known for producing Salua resin called Jhuna. The forest area is also home Kandha tribe settled in Baanda- Padesi, Karod and other villages who extract and collect Jhuna along with collecting several minor forest produces from this forest.
Jhuna, the solidified oleo-resin of Sal trees have wide range of traditional applications. Besides being primarily used  to create a fragrant smoke when sprinkled over burning charcoal that dispels insects, purifies the air and lifts the mood, this substance is traditionally used in healing of wounds and stomach related issues. The resin is an indispensable part of many magico invocations and religious rituals across Indian subcontinent and beyond. Its smoke spawns a kind of  aesthetics to any traditional rituals. 
Sal tree, botanically known as shorea robusta is indigenous to the South East Asian regions and is considered as a multipurpose and climax species. Besides producing Jhuna as resin, its leaves are stitched together to produce bio-degradable plates and cups used extensively in community feasts. Oil and fat are extracted from its seeds. And yes, the tree is famous for its quality, hard timber. 
The oleo-resin secretes in response to the injury on the tree’s body for healing as well as for protection from various insects. The resinous nature of Sal wood imparts durability and water resistance to it. The resins are tapped by removal of several narrow strips of the bark, at a height of 90-120 cms above the ground. This results in the formation of a groove which gets filled up with exudates in 10-12 days. The initial resin is discharged as a whitish liquid but turns brown when it comes in contact with air. For tapping, trees with girth between 0.9 to 1.8 meters are selected. Although, the tapping can be done throughout the year, obtaining three lots is a standard  practice. The first lot in June-July is of best quality followed by the one in October, and the last in January. Cooler climate is preferred to facilitate the resins remaining pure without getting contaminated with dirt. 

“The trunk diameter above 120 cms is considered to be mature. A minimum diameter of 160-200cms is ideal for Jhuna collection. Often there is no need of cutting or making incisions on the trunk. Jhuna (resin) deposits at natural cracks through top to bottom of the whole trunk. It naturally flows out and hardens,” says Prasanna Kumar Patra, who serves as the Forester of that area. 
Besides Odisha, Sal forests are found in states of Jharkhand, Bihar, Chhattisgarh, Uttarakhand, Andhra Pradesh, Tripura Odisha, Maharashtra, Sikkim, Assam, Meghalaya, Haryana, Himachal Pradesh, Uttar Pradesh, Madhya Pradesh, and West Bengal. Sal or Sakhua is the state tree of Chattisgarh and Jharkhand,
Sal trees can be up to 30-35 m tall having trunk diameter of   2- 2.5 m. The crown is spreading and spherical. The bole is clean, straight, and cylindrical, but often bearing branches. Its bark is dark brown and thick, leaves are shiny, glabrous, elongated and broadly oval at the base. This is why it is called Maricha Patraka in Sanskrit. Sal is evergreen and deciduous. It sheds its leaves in February-March, which grows again in April-May.
In the traditional Siddha system of medicine, there lies a concept of Yegha Mooligai Prayogam, which literally translates into use of single herb as a therapeutic agent especially in conditions linked to menorrhagia, leucorrhoea, dysentery and healing of wounds, cuts and burns. The use of oleo-resin from Sal tree, known traditionally as kungliyam has been endorsed for above conditions.
Jhuna, also known as Dhuna or Laldhuna in other parts of India, is used as a natural, traditional fumigant up to three times a day in many households as a behavior-modifying substance which not only elevates mood, but also keeps away mosquitos and other insects. In earlier times, texts have depicted drying    of hair with its fumes which apart from its benefits to health also adds a unique fragrance. Jhuna was termed as Agnivallabha as the resin catches fire easily. For being an exudate or rala niryasa spreading good fragrance, the ancient tribes called it Yakshadhoopa or Sooradhoopa.
Microscopical studies of the Jhuna shows presence of resin with irregular shape, translucent, and reddish tannin contents, yellow coloured oil globules. Phytochemical analyses show a wide array of organic compounds which lend it its healing properties. S. robusta resin has been reported to contain several mono-, sesqui- and tri-terpenoids that includes ursolic acid, tri and tetrahydroxy ursenoic acid, asiatic acid, á and â-amyrin, á–amyrenone, mangiferonic acid, benthamic acid and uvaol. Methanol extraction showed highest response in term of sensitivity and inhibiting bacteria, thus implying its potential for use as a natural antibacterial agent.
Ayurveda texts like Charaka Sanhita, Sushruta Sanhita, Dhanwantari Nighantu and Bhavaprakasha Nighantu explain about its use in fracture healing (Bhagnasandhana Bruta), anti-toxic (Visa-ha), and cleanser of wounds, boils and healing (Vranashodhana), and as anti-itching therapy (Kandunashana).
In regions of Ganjam and Kandhamala, pure Jhuna is mixed with warm cow’s milk and ingested to get relief from severe body ache. Its vapors are said to be useful in treating chickenpox. “The body is covered with bed sheet and the jhuna vapors are pushed inside. It warms the body and gives a great sense of relief. It is done twice daily for up to 4-5 days which leads to the drying up of the pustules and the skin gets rejuvenated. There is almost no itching,” says Prasanna Patra.
It was found that triterpene-rich fraction and essential oil of S. robusta have the highest wound healing activities thus confirming the traditional claims of wound healing properties of this species. According to Ayurveda, the bark and leaves of S. robusta are used to cure itching, leprosy, gonorrhea, wounds and stomach ulcers, disease of vagina, cough, pain in ear and head. It is used as anthelmintic, alexeteric, enrich the blood, prevent sweating, and improve the complexion.  When mixed with beeswax as the base, Sal oleo-resin is used to treat foot crack, ulcers, wounds, burns, and ear and eye troubles, skin disease. When mixed with pure cow ghee it is used to relive and treat hemorrhoids. The presence of phenols, tannins and flavonoids lend its use as an analgesic for chronic pain and anti-inflammatory conditions.
Ancient practices of healing by using the Sal resin as one of the components were passed on from one generation to another which continued on for hundreds of years and even influence later systems of Unani and modern medicine.  Even to this day, research and bioassays are being carried out at many modern laboratory setups for eliciting more data about its anti-lipidemic, anti-cancer and immune-modulating properties.
Well, one cannot but be simply fascinated by the fact  that thousands of years back in the past, the ancient elders understood and implemented the use of the oleo resin as well as other parts of the plant in healing. Our present day connection with Sal and many similar trees is perhaps an epigenetic memory that keeps drawing us to this wondrous tree and its resins. Shala literally means house-which is representative of the place we live in as well as the body which houses an interacting consciousness. 
The Munda, the Kurukh-Dangria and the Oraon people of the Indian subcontinent revere Sal tree. Jhuna is used in all auspicious rituals and as an offering at Shakta shrines. Some tribes have sacred Sal groves and revere Sarna Budhi as the Sacred Woman of the holy grove.  Prasanna Patra says, “In Odisha, Jhuna is an important minor forest product and good collection is seen in areas of Koraput-Jeypore near the Gupteswar forest belt, Kurtamgada-Tumudibandha, Jalespaatta and Kotagada near Kandhamal. But the collection is not much in Kandhamala. The Ganda tribe in Odisha use jhuna heavily in their agrarian based Chaitra festivals. Danda Jatra which is famous in many areas of Odisha also incorporates this auspicious substance in abundance. Bali Jatra observed near Mundigada, Gumma near Belghar, Lanjigarh in Kalahandi and parts of Rayagada district it is used throughout the festival. Jhuna in dhoopa-daani is offered by tribes having sacred groves daily while propitiating there deities and ancestors.”
Over the years, volume of collection has decreased. The primary reasons being increase in population which has led to increase in bagada or podhun cultivation. It is a form of shifting cultivation which renders the chunks of Sal forests barren. “In earlier days Podhun cultivation was not that rampant, the purukhas or elder generations had a vision of responsible consumption and saving things for next generations. Another reason for the decrease in Jhuna collection is collecting practices which aren’t technically sound i.e. felling of the whole tree to collect the oleo resin.
Most of us, holding a packet of Jhuna or Laldhuna and using it on various occasions are not even aware of the connection between man and the bounties nature offers in many forms. Yet, Jhuna is just another natural substance that echoes a deep connection of mankind with nature, the healing and the silent symphonies of the Sal forest. The Giant Squirrel Pattamusa subsists on the fruits of the tall Sal trees whose observatory can be found at Kaliamba near Saluapalli, a two hour drive from Brahmapur in Odisha. A whole ecosystem revolves around these trees involving man, fauna and even tiny insects.