of closing philosophy faculties because of possible harmful effects. In the wake of the Decembrist revolt, the tsar moved to protect the status quo by centralizing the educational system. He wanted to neutralize the threat of foreign ideas and what he ridiculed as "pseudo-knowledge." However, his minister of education, Sergei Uvarov, quietly promoted academic freedom and autonomy, raised academic standards, improved facilities, and opened higher education to the middle classes. By 1848 the tsar, fearing the political upheavals in the West might inspire similar uprisings in Russia, ended Uvarov's innovations. The universities were small and closely monitored, especially the potentially dangerous philosophy departments. Their main mission was to train a loyal, athletic, masculinized senior bureaucracy that avoided the effeminacy of office work. The Imperial Academy of Fine Arts in St. Petersburg grew in importance by its recognition and support of artists. Nicholas I decided to control it personally. He overruled it regarding awarding ranks to artists. He reprimanded and humiliated artists whose works he found distasteful. The result was not better art, but just the reverse, compounded by fear and insecurity among members of the art community. Despite the repressions of this period, Russians outside official control produced a flowering of literature and the arts. Through the works of Aleksandr Pushkin, Nikolai Gogol, Ivan Turgenev and numerous others, Russian literature gained international stature and recognition. Ballet took root in Russia after its importation from France, and classical music became firmly established with the compositions of Mikhail Glinka (1804–1857). Minister of Finance Georg von Cancrin persuaded the emperor of the benefits of inviting Prussian scientist Alexander von Humboldt to Russia to investigate regions that could produce mineral wealth. The Russian government paid Humboldt's expenses for his eight-month expedition through Russia in 1829, which resulted in diamond finds in the Ural mountains. Humboldt published multiple volumes on his Russian expedition, which he dedicated to the tsar despite his increasing disapproval of the tsar's policies. Treatment of Jews In 1851 the Jewish population numbered at 2.4 million with 212,000 of them living in Russian controlled Poland territory. This made them one of the largest inorodtsy minorities in the Russian Empire. On 26 August 1827 the edict of military conscription ("Ustav rekrutskoi povinnosti") was introduced, which required Jewish boys to serve in the Russian military for 25 years from the age of 18. Before that many of them were forcibly conscripted into Cantonist schools