The "black fever" that Dr. Burton is on his way to treat beyond Mandalay is medically known as visceral leishmaniasis. It is the second most prevalent disease caused by parasitic protozoa, and it's spread by sand fly bites, like malaria (the most prevalent) is spread by mosquito bites. In the pre-antibiotic era of this film, Burton's trip would have been most dangerous indeed. Even in the 21st century, existing drugs have serious drawbacks in terms of safety, resistance, stability, and cost. They have low tolerability, long treatment duration when used alone, and are difficult to administer. No vaccines or drugs to prevent infection are available. The best way to prevent infection is to prevent sand fly bites by minimizing outdoor activities at night, wearing protective clothing, and applying insect repellent.
At the time Kay Francis wore the dazzling silver gown, the modern sequin was just being perfected. Early versions of the accent were tiny metal discs, often covered in lead. The design dates back to miniscule golden discs found among Tutankhame's artifacts.
The 10,000 rupees Tanya extorts from Col. Dawson would equate to $3,788 at the time, which would be the equivalent of $67,000 in 2015.
This film was approved before strict Code enforcement began in July 1934. The studio's 1936 application for a certificate of approval for re-issue was denied. A letter from Joseph Breen, Director of the Studio Relations office of the AMPPA to Jack L. Warner dated 3 Sep 1936 said that any attempt to re-edit the film to bring it within the requirements of the Production Code would be extremely difficult, and "This picture also has the basic Code violation of presenting the heroine as an immoral woman."