In the Chaldæan creed all diseases were the work of demons. This is why Herodotus found no physicians in Babylon and Assyria. There was no science of medicine; “it was simply a branch of magic, and was practised by incantations, exorcism, the use of philters and enchanted drinks.”[210] Of course the priests made it their business to compound their drinks of such drugs as they had discovered to possess therapeutic virtue. In ancient times magic and medicine were thus closely united. It could not have been always faith alone which cured the patient, but faith plus a little poppy juice would work wonders in many cases. It became therefore greatly to the interest of the priests and magicians to learn the properties of herbs, and the value of the juices and extracts of plants. Out of evil, therefore, mankind reaped this great and valuable knowledge. The two gravest and most fatal diseases with which the Chaldæans were acquainted, says M. Lenormant,[211] were the plague and fever, the _Namtar_ and the _Idpa_. Naturally they were represented as two demons, the strongest and most formidable who afflict mankind. An old fragment says:— The execrable _Idpa_ acts upon the head of man, The malevolent _Namtar_ upon the life of man, The malevolent _Utug_ upon the forehead of man, The malevolent _Alal_ upon the chest of man, The malevolent _Gigim_ upon the bowels of man, The malevolent _Telal_ upon the hand of man.[212] The use of magic knots as a cure for diseases was firmly believed in by the ancient Chaldees. M. Lenormant[213] gives a translation of one of the formulæ supposed to have been used against diseases of the head. Knot on the right and arrange flat in regular bands, on the left a woman’s diadem; divide it twice in seven little bands; ... gird the head of the invalid with it; gird the forehead of the invalid with it; gird the seat of life with it; gird his hands and his feet; seat him on his bed; pour on him enchanted waters. Let the disease of his head be carried away into the heavens like a violent wind; ... may the earth swallow it up like passing waters! Sir Henry Rawlinson has discovered that there were three classes of Chaldæan doctors, exactly in accordance with the enumeration of the prophet Daniel. These were the _Khartumim_, or conjurors, the _Chakamim_, or physicians, and the _Asaphim_, or theosophists (see Daniel ii. 2; v. ii). The Babylonian doctrine of disease was that the hosts of evil spirits in the air entered man’s body, and could only be expelled by the incantations of the exorcist. These disease-demons were addressed as “the noxious neck spirit,” “the burning spirit of the entrails which devours the man.” Headache was caused by evil spirits which were commanded by the charmer to fly away “like grasshoppers” into the sky.[214]