10*2 Mr. Crosse s Electrical Experiments. 



mere chance, in consequence of its partial porosity, and Mr. 

 Crosse did not believe that it had the slightest effect in the 

 production of the insects. The fluid with which the basin 

 was filled was made as follows : — A piece of black flint having 

 been exposed to a red heat, and quenched in water, to make 

 it friable, was reduced to powder, two ounces of which were 

 intimately mixed with six ounces of carbonate of potassa, and 

 the compound was exposed to a strong heat for 15 minutes 

 in a black lead crucible, in an air furnace. In this fused state 

 it was poured on an iron plate, reduced to powder, whilst still 

 warm, and boiling water poured upon it ; it was then kept 

 boiling for some minutes in a sand bath. The greater part of 

 the soluble glass thus formed was taken up by the water, to- 

 gether with a portion of alumina from the crucible, ( a silver 

 one would have been used but Mr. Crosse had none sufficient- 

 ly large.) To a portion of the silicate of potassa thus formed 

 boiling water was added to dilute it ; and then slowly, to su- 

 persaturation, hydrochloric acid. This fluid was subjected 

 to a long-continued electric action, through the intervention 

 of a porous stone, in order that, if possible, crystals of silica 

 might be formed at one of the poles of the battery; but Mr. 

 Crosse failed in accomplishing this by these means. On the 

 fourteenth morning from the commencement of the experi- 

 ment, were observed, through a lens, a few small whitish ex- 

 crescences or nipples, projecting from about the middle of the 

 electrified stone, and nearly under the dropping of the fluid 

 above. On the eighteenth day these projections were enlar- 

 ged, and seven or eight filaments, each of them larger than 

 the excrescence from which it grew, made their appearance 

 on each of the nipples. On the twenty-second day these ap- 

 pearances were more elevated and distinct, and on the twen- 

 ty-sixth day each figure assumed the form of a perfect insect, 

 standing erect on a few bristles which formed its tail. Until 

 this period Mr. Crosse had no notion that these appearances 

 were any other than an incipient mineral formation, but it was 

 not until the twenty-eighth day, when he plainly perceived 

 the little creatures move their legs, that he felt any surprise ; 

 and when this occurred, as may be easily imagined, he was 

 not a little astonished. Mr. Crosse endeavoured to detach 

 with the point of a needle one or two of them from their po- 

 sition on the stone, but they immediately died, and he was 

 obliged to wait patiently for a few days longer, when they se- 

 parated themselves from the stone, and moved about at plea- 

 sure, although they had been for some time after their birth 

 apparently averse to motion. In the course of a few weeks, 

 about a hundred made their appearance on the stone. At 



