Happily for the people, the empire of the East possessed vast natural advantages, which, in some measure, counteracted the injurious effects of heavy taxation. Blessed by nature with superior soil, situation, and climate, her people could bear burdens which would have ruined the inhabitants of countries less favourably situated. Embracing the nations Rome had conquered, from the Adriatic to the frontiers of Æthiopia and Persia, the capital of the East had the means within herself, in spite of tariffs, apparently ruinous, of creating and maintaining an extensive and lucrative inland and maritime commerce. Egypt still largely supplied her with corn, and afforded many other advantages; commerce gradually extended itself along the coast of the Mediterranean; and as her own wants in food and dress were many, these combined, afforded a large and varied field for employment. The Asiatic love of dress was duly—if not unduly—exhibited by the ladies of Constantinople; and if Aurelian complained that a pound of silk at Rome cost twelve ounces of gold, we may well believe that Justinian saw with concern the Persians intercepting and obtaining a monopoly of this important trade, and the wealth of his subjects continually drained by a nation of fire-worshippers. [Sidenote: Silk trade.] An unexpected event, however, afforded Justinian the means of cultivating in his own dominions that much prized article. Christian missionaries were then, as they have often been since, the harbingers of commerce, as well as of peace and good-will towards all men. Some of them who had settled at Ceylon, or, perhaps, more probably on the coast of Malabar, were induced, with a view of proselytising the Pagans, to follow the footsteps of trade to the extremities of Asia. Two of their number remained in China, and, in the course of their missionary occupations, observed that the common dress of the Chinese consisted of silk, at the same time noticing the myriads of silkworms, whence the raw material was produced. Having carefully collected a large number of the eggs in a hollow cane, they conveyed them to Constantinople, and, imparting their discovery to Justinian, were liberally rewarded, and encouraged to pursue the propagation of the valuable insect. Under their direction the eggs were hatched at the proper season by the artificial heat of dung; and the worms thus produced living and labouring in a foreign climate, Europe ceased to be dependent for her supply of this now necessary article on the chances of war or of Asiatic caprice.[347] [Sidenote: Naval expedition of Justinian against the Vandals, A.D. 533, and conquest of Carthage.]