Boric acid (H₃BO₃) was locally heated in a test tube using infrared radiation to observe its dehydration behavior during heating.
Infrared irradiation causes water bound within the solid to separate and be released as liquid water, which subsequently turns into water vapor and migrates.
This video demonstrates that infrared local heating supplies energy to the interior of a solid, allowing internal reactions and dehydration to proceed even without reaching melting.
It serves as a suitable demonstration for understanding the characteristics of non-contact internal heating occurring in a short time.
Please check the following site for more information.
Related page:
Internal Dehydration Phenomena of Borax by Local Infrared Heating 
Infrared Local Heating for Rapid Melting of Lead Plate 
Infrared Local Heating for Rapid Melting of Zinc Plate 
Melting of Citric Acid in a Test Tube by Infrared Heating 
Heat transfer in stainless steel screws visualized by infrared local heating 
Rapid Melting of Black Lead Glass Rod by Localized Infrared Heating 
Rapid Vaporization of Candle by Infrared Heating 
Melting Aluminum Wire by Infrared Heating Enhanced with Blackbody Coating