Stalin faced several severe health problems; an 1884 smallpox infection left him with facial pock scars, and aged 12, he was seriously injured after being hit by a phaeton, which was the likely cause of a lifelong disability to his left arm. In August 1894, Stalin enrolled in the Spiritual Seminary in Tiflis, enabled by a scholarship that allowed him to study at a reduced rate. Here he joined 600 trainee priests who boarded at the institution. Stalin was again academically successful and gained high grades. He continued writing poetry; five of his poems were published under the pseudonym of "Soselo" in Ilia Chavchavadze's newspaper "Iveria" ('Georgia'). Thematically, they dealt with topics like nature, land, and patriotism. According to Stalin's biographer Simon Sebag Montefiore they became "minor Georgian classics", and were included in various anthologies of Georgian poetry over the coming years. As he grew older, Stalin lost interest in priestly studies, his grades dropped, and he was repeatedly confined to a cell for his rebellious behaviour. The seminary's journal noted that he declared himself an atheist, stalked out of prayers and refused to doff his hat to monks. Stalin joined a forbidden book club at the school; he was particularly influenced by Nikolay Chernyshevsky's 1863 pro-revolutionary novel "What Is To Be Done?". Another influential text was Alexander Kazbegi's "The Patricide", with Stalin adopting the nickname "Koba" from that of the book's bandit protagonist. He also read "", the 1867 book by German sociological theorist Karl Marx. Stalin devoted himself to Marx's socio-political theory, Marxism, which was then on the rise in Georgia, one of various forms of socialism opposed to the empire's governing Tsarist authorities. At night, he attended secret workers' meetings, and was introduced to Silibistro "Silva" Jibladze, the Marxist founder of Mesame Dasi ('Third Group'), a Georgian socialist group. Stalin left the seminary in April 1899 and never returned. In October 1899, Stalin began work as a meteorologist at a Tiflis observatory. He attracted a group of supporters through his classes in socialist theory, and co-organised a secret workers' mass meeting for May Day 1900, at which he successfully encouraged many of the men to take strike action. By this point, the empire's secret police — the Okhrana — were aware of Stalin's activities within Tiflis' revolutionary milieu.