Yingxue congshuo 螢雪叢說 "Dense talks bright as glowworms and snow" is a "brush-notes"-style book (biji 筆記) written during the Southern Song period 南宋 (1127-1279) by Yu Cheng 俞成 (fl. 1150), courtesy name Yuande 元德. He hailed from Dongyang 東陽 (modern Jinhua 金華, Zhejiang) and failed to pass the state examination. He therefore decided, aged more than forty, to study literature and to note down his thoughts that shone like "reflections of snow and a bag full of glowworms" (nang ying ying xue 囊螢映雪). A book based on these reflections was able, he said, to demonstrate that his scholarship was still brilliant and his wit still sharp.
His 2-juan-long book therefore speaks a lot about the difficulties of learning and the preparation for the state examinations. Yu Cheng discusses historiography, exegesis, poetry, prayers, sacrificial texts, rhapsodies, phonology and the composition of poems, and about competent persons at the imperial court that were underrated by historians, and many other themes of relevance to education, scholarship and the life of state officials, all in all sixty chapters. The compilers of the imperial series Siku quanshu 四庫全書 criticized Yu Cheng's book for its failure to understand great matters. It is nevertheless an important source for the analysis of Song period scholars' preparation for official career.