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Memorials, Scientific and Literary of Andrew Crosse, the Electrician – Cornelia and Andrew Crosse

"As to the appearance of the acari under long-continued electrical action, I have never in thought, word, or deed, given any one a right to suppose that I considered them as a creation, or even as a formation, from inorganic matter. To create is to form a something out of a nothing. To annihilate, is to reduce that something to a nothing. Both of these, of course, can only be the attributes of the Almighty.

In fact, I can assure you most sacredly that I have never dreamed of any theory sufficient to account for their appearance. I confess that I was nor a little surprised, and am so still, and quite as much as I was when the acari made their first appearance. Again, I have never claimed any merit as attached to these experiments. It was a matter of chance. I was looking for silicious formations, and animal matter appeared instead. The first publication of my original experiment took place entirely without my knowledge…………………………

"In a great number of my experiments, made by passing a long current of electricity through various fluids (and some of them were considered to be destructive to animal life), acari have made their appearance; but never excepting on an electrified surface kept constantly moistened, or beneath the surface of an electrified fluid.

In some instances these little animals have been produced two inches below the surface of a poisonous liquid. In one instance they made their appearance upon the lower part of a small piece of quartz, plunged two inches deep into a glass vessel of fluo-silicic acid, or, in other words, into fluoric acid holding silica in solution. A current of electricity was passed through this fluid for a twelvemonth or more; and at the end of some months three of these acari were visible on the piece of quartz, which was kept negatively electrified.

I have closely examined the progress of these insects. Their first appearance consists in a very minute whitish hemisphere, formed upon the surface of the electrified body, sometimes at the positive end, and sometimes at the negative, and occasionally between the two, or in the middle of the electrified current; and sometimes upon all. In a few days this speck enlarges and elongates vertically, and shoots out filaments of a whitish wavy appearance, and easily seen through a lens of very low power. Then commences the first appearance of animal life.

If a fine point be made to approach these filaments, they immediately shrink up and collapse like zoophytes upon moss, but expand again some time after the removal of the point.

Some days afterwards these filaments become legs and bristles, and a perfect acarus is the result, which finally detaches itself from its birth-place, and if under a fluid, climbs up the electrified wire, and escapes from the vessel, and afterwards feeds either on the moisture or the outside of the vessel, or on paper or card, or other substance in its vicinity. If one of them be afterwards thrown into the fluid in which he was produced, he is immediately drowned.

 (Here follows an account of an experiment which is detailed in a note at the end of the volume.)

"Conflicting opinions have existed, as to whether the acarus developed under the above circumstances be of a new description or not. I know not whether this may be of any consequence, as it is very easy for so minute an animal to have escaped particular observation; and besides, I have observed a variety amongst the acari so produced; but this I leave to entomologists. I have never before heard of acari having been produced under a fluid or of their ova throwing out filaments; nor have I ever observed any ova previous to or during electrisation, except that the speck which throws out filaments be an ovum; but when a number of these insects, in a perfect state, congregate, ova are the result.

I may now remark that in several of these experiments fungi have made their appearance, and in some cases have been followed by the birth of acari. In one instance a crop of fungi was produced upon the upper end of a stick of oak charcoal, plunged into a solution of silicate of potash, kept negatively electrified for a considerable time, and covered by a bell-glass inverted over it in a dish of mercury. The charcoal before being used was taken red-hot from a fire. There is evidently a close connection between animal and vegetable life: but one thing is necessary to be observed, that such experiments as those I have just touched on must be varied in every possible form, and repeated over and over again with unflinching perseverance, and with the most sharp-sighted caution, in order to attain satisfactory results.

In conclusion, I must remark, that in the course of these and other experiments, there is considerable similitude between the first stages of the birth of acari and of certain mineral crystallisations electrically produced. In many of them, more especially in the formation of sulphate of lime, or sulphate of strontian, its commencement is denoted by a whitish speck so it is in the birth of the acarus. This mineral speck enlarges and elongates vertically: so it does with the acarus. Then the mineral throws out whitish filaments: so does the acarus speck. So far it is difficult to detect the difference between the incipient mineral and the animal; but as these filaments become more definite in each, in the mineral they become rigid, shining, transparent sixsided prisms; in the animal they are soft and having filaments, and finally endowed with motion and life. I might add much more to the above sketch, but it would be more fit for a pamphlet than for a letter.