AMERICAN INSTITUTE. 453 



tre ; at tlie end of three weeks a perfect fly issued from It, and took no no- 

 tice of a spider that was placed in the bottle, until three days had elapsed, 

 when it deposited an egg in the creature's body, precisely as its parent had 

 done before ; this egg did not come to maturity. Thei'e is a parasite ani- 

 malcule, having a long body, abdomen, with two arms and four legs, thorax 

 and head, existing in the sebaceous follicles or cutecular cells of every hu- 

 man being ; they are very numerous in the depressions on each side of the 

 nose, and on the breast and back. During sickness they increase rapidly, 

 and after death abound. 



Nearly all microscopic animalcules are complicated in their orcvanizatiou. 

 They form two classes entirely different from each other. Their distribu- 

 tion, geographically speaking, is governed by the same laws that govern 

 other animals. They color water, and emit phosphorescent lii-ht in the 

 sea they inhabit. Fifty millions of them may be counted in a square inch 

 of liquid. They possess wonderful generative powers, as a single individ- 

 ual has been known to produce several millions like itself in a few hours. 

 They constitute rocks, stones, earth, whiting, ochre, &c., by their silicious 

 outer coverings. They cause water to become impure, kill fish, induce mi- 

 asma, cholera, yellow fever, and all contagious diseases. They are always 

 in motion, and never sleep. Men and animals are full of them, and they 

 again are tormented with parasites. They abound in the atmosphere, and 

 we breathe them at every breath. The deposits in all the rivers and har- 

 bors of the earth, generally attributed to the accumulation of solid earth, 

 is no doubt mainly the produce of animal organisms. The red-colored 

 snow of the Alps is caused by them ; in it they deposit their ego-s, which 

 develop and reproduce abundantly. Four millions may be included in a 

 grain of M'heat. They are single-celled organisms. Last year an immense 

 cloud passed over Shanghai, from which an impalpable powder fell upon 

 the city, which, on being submitted to the microscope, proved to be spores 

 of a confervoid plant, which vegetated in the Chinese sea, and imparted to 

 it a peculiar color. A shower of dust alighted on a ship's deck near the 

 Cape de Verde Islands, which proved to be minute organisms known as 

 dialomaceas. A sample of dust from a similar cloud collected on a ship's 

 deck, five hundred miles from the coast of Africa, exhibited, under the 

 microscope, many species of fresh water and marine diatoms filled with life 

 and there is no doubt resting in my mind but that they were developed in 

 the air. Last summer I was standing on my piazza at sunrise, looking to- 

 wards the Hudson river, but saw nothing in the atmosphere to elicit atten- 

 tion, but moving a few feet, a column obstructed my view of the sun, when 

 to my amazement I found the air, as far as I my eye could reach, filled 

 with minute insect life, which could not be seen in any other position. On 

 wetting a shingle and passing it quickly through the air, a great number 

 adhered, and though amazingly small, each individual had a parasite at- 

 tached to it. Being an unbiased observer, I was stimulated to make sun. 

 dry examinations of atmospheric organisms and their progressive self-de- 

 velopment, which at a proper time will be revealed. 



