36 PHILOSOPHICAL TRANSACTIONS. [anNO 1684. 



These pores being thus made and secured, form a very convenient and open 

 passage for the discharge of the more noxious and perspirable parts of the blood, 

 which by the continual use of the hands and feet, are plentifully brought into 

 them. Whence it is that the sweat of the feet, in many people, is much more 

 offensive than that of any other part of the body. And that many hypochon- 

 driacal men, and hysterical women, have almost a continual burning in the soles 

 of their feet, and the palms of their hands. 



Abstract of a Letter from Mr. Anthony Leuivenhoeck, at Delft, dated Sept. 17, 

 l683 : Containing some Microscopical Observations, about Animals in the Scurf 

 of the Teeth, the substance called JVorms in the Nose, and the Cuticula consisting 

 of Scales. N° 159, p. 308. 



Though my teeth are kept usually very clean, yet when I view them in a 

 magnifying glass, I find growing between them a little white matter^ as thick as 

 wetted flour : in this substance though I could not perceive any motion, I 

 judged there might probably be living creatures. I therefore took some of this 

 flour, and mixed it either with pure rain water wherein were no animals, or 

 else with some of my spittle, having no animals nor air bubbles to cause a mo- 

 tion in it; and then to my great surprize perceived that the aforesaid matter 

 contained very many small living animals, which moved themselves very 

 strangely. The largest sort were not numerous, but their motion strong and 

 nimble, darting themselves through the water or spittle, as a jack or pike does 

 through the water. The 2d sort spun about like a top, and were more in num- 

 ber than the first. In the 3d sort I could not well distinguish the figure, for 

 sometimes it seemed to be an oval, and other times a circle : these were ex- 

 ceedingly small, and so swift, that I can compare them to nothing better than a 

 swarm of flies or gnats, flying and turning among each other in a small space. 

 Of this sort I believe there might be many thousands in a quantity of water no 

 larger than a sand, though the flour were but the Qth part of the water or 

 spittle containing it. Besides these animals, there were a great quantity of 

 streaks or threads of different lengths, but of like thickness, lying confusedly 

 together, some bent, and others straight. These had no motion or life in 

 them. 



I observed the spittle of two several women, whose teeth were kept clean, 

 and there were no animals in the spittle; but the meal between the teeth, being 

 mixed with water, as before, I found the animals above described, as also the 

 long particles. The spittle of a child of 8 years old had no living creatures in 

 it; but the meal between the teeth had a great many of the animals above de- 

 scribed, as also the streaks. The spittle of an old man that had lived soberly, 



