Dr. Mead, in his treatise on the diseases of old age,[188] thus explains the curious figurative phrases. By the darkening of the sun, moon, and stars, he says we are to understand the obscuration of the mental faculties, which is so common in advanced life. The clouds returning after rain symbolise the cares and troubles which oppress the aged; especially when the vigour of the mind is lessened, so that they cannot cast them off. From the mind we pass to the body: “the keepers of the house shall tremble,” etc. That is to say, the limbs which support the body grow feeble and relaxed, and are incapable of defending us against injuries. The grinders are the molar teeth. The failing sight is compared to the darkness which meets those who look out of the windows. By diminished appetite the mouth, which is the door of the body, is less frequently opened than in youth. The sound of the grinding of the teeth is low, because old people have, in the absence of them, to eat with their gums. The rising up at the voice of the bird signifies the short and interrupted sleep of the aged. By the daughters of music we are to understand the ears, which no longer administer to our pleasure in conveying harmonious sounds. The sense of feeling is diminished, and the aged are fearful of stumbling in the way. The early flowers of spring shall flourish in vain. The phrase, the grasshopper shall become a burden, according to Dr. Mead, is the modest Hebrew mode of describing the effects of scrotal rupture. He says the grasshopper is made up chiefly of belly, and when full of eggs bears some resemblance to a scrotum smitten by a rupture. “Desire shall be lost” is like Ovid’s _Turpe senilis amor_, and does not refer to appetite for food. The loosened silver cord is the vertebral column; the medulla oblongata is of a silver or whitish colour. The golden bowl expresses the dignity of the head, from which in old age come defluxions to the nose, eyes, and mouth. Incontinence of urine is a common trouble of the aged, well expressed by the figure of the pitcher broken at the fountain; and the wheel at the cistern, to those who knew nothing of the circulation of the blood, fairly describes the failing heart, no longer capable of propelling the stream of life through the vessels. Referring to the words, “The sun shall not smite thee by day, nor the moon by night” (Psalm cxxi. 6), Captain Burton says[189] that he has seen a hale and hearty Arab, after sitting an hour in the moonlight, look like a man fresh from a sick-bed; and he knew an Englishman in India whose face was temporarily paralysed by sleeping with it exposed to the moon.