In order to accelerate the condensation of the brine, the salt-maker adds and mixes into it bullock’s blood, or calf’s blood, or buck’s blood, which dissolves and is distributed into all the corners of the caldron. When the boiling water seems to be mixed with scum, it is skimmed with a ladle, and from the firing of the furnace to the skimming of the boiling scum is the work of half an hour. After this it boils down for another quarter of an hour, and thereafter it begins to condense into salt. When the brine commences to thicken with the heat, it is stirred assiduously with a wooden spatula, and then allowed to boil for an hour. At this stage beer is added to the contents of the caldron, which is protected from the wind by boards, and the salt is then withdrawn with a shovel and thrown into baskets. The remaining brine is allowed to boil for another three-quarters of an hour, when the salt is again removed and placed in the drying compartment. In this manner the salters alternately boil the brine and collect the salt, “day and night, with the exception only of the annual feast days.” No caldron is able to stand the fire for more than half a year. New caldrons are washed out three times in the first two weeks, and afterwards once a week. In this manner the incrustations fall from the bottom of the caldron, and if this is not done the salt would have to be made more slowly over a fiercer fire, which not only requires more brine but burns the plates of the caldron. If any cracks make their appearance in the caldron, they are filled up with cement. The salt made during the first two weeks in a new caldron is usually inferior in quality, being stained by the rust at the bottom where incrustations have not yet adhered. Agricola’s description is full of technical exactness in regard to those parts of the apparatus and the process which are of comparatively insignificant interest, but it is, unfortunately, silent about details on which fuller information would be useful. He tells us the capacity of the tubs in which the brine is conserved, but not of the caldrons in which it is boiled, and we cannot calculate the quantity by the dimensions of the receptacles, since he omits to mention the depth to which they are filled. He explains that it takes half an hour to fill the baskets with the salt that is drawn from the caldron, but as he does not give us the dimensions of the baskets employed, or the amount of wood or straw consumed, we cannot determine the length of time required to make a certain quantity of salt, or the cost in fuel. But, condensed and simplified by the elimination of extraneous particulars and complex technicalities, the foregoing enables us to obtain a fair idea of the methods employed by the salter of Halle, in Saxony, assisted by his wife as helper and a youthful stoker--working naked, on account of the great heat, save for a straw cap and a breech cloth--in the first half of the sixteenth century.