Page:The Works of William Harvey (part 1 of 2).djvu/489

 That this mucaginous matter differs greatly from the ichorous or watery part of the blood, which, as if colder than the rest, subsides to the bottom of the basin, appears on two distinct grounds : for the watery and sanious portion is too crude and unconcocted ever to pass into purer and more perfect blood ; and the thicker and more fibrous mucus swimming above the clot of the blood itself appears more concoct and better elabo- rated than this ; and so in the resolution or separation of the blood it comes that the mucus occupies the upper place, the sanies the lower; the clot and red parts, however, both those of a brighter and those of a darker colour, occupy the middle space.

For it is certain that not only this part, but the whole blood, and indeed the flesh itself as may be seen in crimi- nals hung in chains may be reduced to an ichorous sanies ; that is to say, become resolved into the matters of which they were composed, like salt into the lixivium from which it had been obtained. In like manner, the blood taken away in any cachexy abounds in serum, and this to such an extent that occasionally scarce any clot is -seen the whole mass of blood forms one sanies. This is observed in leucophlegmatia, and is natural in bloodless animals.

Further, if you take away some blood shortly after a meal, before the second digestion has been completed and the serum has had time to descend by the kidneys, or at the com- mencement of an attack of intermittent fever, you will find it sanious, inconcoct, and abounding in serum. On the contrary, if you open a vein after fasting, or a copious discharge of urine or sweat, you will find the blood thick, as if without serum, and almost wholly condensed into clot.

And in the same way as in coagulating blood you find a little of the afore-mentioned supernatant mucus, so if you ex- pose the sanies in question, separated from the clot, to a gentle heat over the fire, you will find it to be speedily changed into the mucus ; an obvious indication that the water or sanies which separates from the blood in the basin, is perchance a certain element in the urine, but not the urine itself, although in co- lour and consistence it seems so in fact. The urine is not co- agulated or condensed into a fibrous mucus, but rather into a lixivium ; the watery or sanious portion of the urine, however, when lightly boiled, does occasionally run into a mucus that swims