VOL. XLV.] PHILOSOPHICAL TRANSACTIONS. 605 



quently move and detach itself from a much less absolutely quiescent : they did 

 not seem to be enascent embryo animals, from a deposition of any extraneous 

 spawn; for the phials had been closed with corks ; nay, they were in the very 

 seed, or the almond-germ particles themselves. 



These same observations Mr. de BufFon made himself; for they examined 

 these infusions together a '2nd time at his house ; and then it was that he ordered 

 15 seed infusions to be made up, which they continued regularly to examine 

 twice a week, till Mr. N. proposed to him to take them home, and follow them 

 more closely by a daily or hourly inspection, if necessary. The result of the 1 st 

 observations was, that though the phials had^ been close stopped, and all com- 

 munication with the extei-ior air prevented, yet, in about 15 days time, the in- 

 fusions swarmed with clouds of moving atoms, so small, and so prodigiously 

 active, that though he made use of a magnifier of not much above half a line 

 focal distance, yet he was persuaded nothing but their vast multitude rendered 

 them visible. It seemed therefore as if the first teeming languid particles they 

 had observed, vast in their dimensions, if compared with those they saw, had 

 broken and divided into this immense multitude of microscopical active atoms. 

 Then it was that they began to lay down a distinction between animated and 

 mere organized bodies ; which, though far from being at this time groundless, 

 yet afterwards proved to be false. These, and the spermatic animals, they sup- 

 posed to be of the latter kind; and to be produced in their respective fluids, by a 

 coalition of active principles, much as he had seen the calamary machines 

 formed by hundreds, though absolutely detached, and swimming at liberty in 

 the milt of the fish: while they thought, on the contrary, that the ordinary mi- 

 croscopical animalcules, with strong characteristics of spontaneous motion and 

 animation, were to be classed among animals, and imagined them to proceed 

 from parent individuals of their own species. It was not till some time after 

 this, that, determined to convince himself and others, without any possibility of 

 doubt, whether these moving atoms were really produced from without, or from 

 the very substance infused : he discovered all the common microscopical animal- 

 cules, the spermatic ones not excepted, were to be ranged in the same class, 

 and that their generation was very different from that of all other animated 

 beings. 



For his purpose therefore, he took a quantity of mutton gravy hot from the 

 fire, and shut it up in a phial, closed up with a cork so well masticated, that his 

 precautions amounted to as much as if he had sealed the phial hermetically. He 

 thus effectually excluded the exterior air, that it might not be said the moving 

 bodies drew their origin from insects, or eggs floating in the atmosphere. He 

 would not instil any water, lest, without giving it as intense a degree of heat, it 

 might be thought these productions were conveyed through that element. Seeds 



