374 PHILOSOPHICAL TRANSACTIONS. [aNNO I/O/. 



juices which go into our bodies, have such an affinity with the serum of the 

 blood, as to hinder its separation, and so keep the blood in such a fluid state, 

 that the distemper which we call a fever is thereby prevented. 



Concerning the Whiteness on the Tongue in Fevers, &c. By Mr. Anthony Van 

 Lewmenhoeck, F.R.S. N° 312, p. '245d. 



In the beginning of last September I was seized by a violent fever, which 

 however lasted only three days: on the fourth day I viewed my tongue with i 

 magnifying looking-glass, and observed that it was all over covered with white- 

 ness, only about a finger's breadth of the tip was of its natural colour ; this 

 whiteness is judged by most people to proceed out of the stomach or bowels, 

 by the swelling of the guts, or else from a sharp humour out of the head. I 

 scraped oflT a little with a penknife, and placed it before a microscope, when I 

 perceived that this white matter has no analogy or agreement with that which 

 is coagulated upon the tongue from without, but that it is certainly protruded 

 out of the tongue, as it appeared to me very plainly, when I viewed it with my 

 microscope; for I could then observe, that it was not only closely united to the 

 tongue, but that it was also forced out of it, just as plants proceed from the 

 earth: yea, that it extended itself into boughs and branches, like other plants ; 

 and I have observed such out sproutings as looked like flowers ; and whereas 

 my fever had left me about a day or two before I scraped off the white matter 

 from my tongue, I imagined that the extreme parts of the aforesaid matter were 

 almost worn or rubbed off when I made that observation. 



There was so much to be observed in all these particles, which I had scraped 

 from my tongue, that it was impossible for any painter to describe them ; they 

 seemed outwardly to be convex, and were as transparent as crystal, that is, at 

 the very time I took them from my tongue and viewed them with a microscope ; 

 but when dry, they did not appear so neat; which was occasioned by the slimy 

 or glutinous matter which we have always in our mouths, and which makes these 

 particles cleave together. That I might free them from the glutinous matter or 

 spittle, I put them into a little rain water, and stirred it gently about, that the 

 said matter might be diluted and united to the water; I then took some of those 

 particles, which by their weight had subsided to the bottom, and placed them 

 before a microscope, when I observed with wonder, how very strongly they 

 were fastened to my tongue when I scraped them from it, and that though I had 

 let them lie eight days in water, they were as strong as when they were first 

 taken off. 



* Hearing that a young man was so grievously troubled with the thrush, that he 

 could scarcely draw his breath, I sent to his doctor, and desired him to let me 



