Zhang Xi-ju, styled Ling Shao, was a native of Qiantang (present-day Hangzhou City) during the late Ming and early Qing dynasties. He inherited his family's scholarly tradition; his late father, Mr. Zhang Dazhang, had compiled various medical texts and left behind his handwritten notes, once saying to Xi Ju: "You should strive to carry on my legacy." Xi Ju followed his father's dying wish, studying diligently day and night, and became a disciple of the renowned physician Zhang Zhi-cong, specializing in the study of cold-damage disease. His medical skills advanced greatly, and he was able to cure difficult and severe illnesses with his treatments, surpassing the abilities of contemporary doctors. He authored the six-volume "Direct Interpretation of Cold-Damage Disease Theory," published in the 51st year of the Kangxi era (1712 AD). This book uses the theories of the Neijing to elucidate the doctrines of Zhongjing, presenting complex ideas in a simple and practical manner, offering much enlightenment.