from 7 to 9, and gave light as bright as that of a full Moon behind a very thin cloud; the whole sky was of that color which is occasioned by a fire set at a distance in the night. It was observed in many places in Germany. At Rome it was said to exceed all, in brightness, ever known. Mr. Thos. Shot observed it at London, and says: "The western quarter was of a blood-red color, with streams of a very beautiful bright red, not running in the usual manner, but waving like vapors; the clouds were of a dark-red color; beneath a cloud from whence these streams came was a brightness superior to that of a full Moon." He could see to read in a Bible (Philos. Trans. v. 8). Several persons have told me they remember a remarkable northern light about so long ago, but have met with none.that can determine the exact time. They have a notion it was the second ever seen; they say it was exceeding bright and extensive. One of my neighbors, an intelligent man, remembers it perfectly well, and describes it much as above. He says it appeared soon after sunset, was exceedingly red, the corruscations appeared like the rolling of the waves of the sea, and he could see to read; that it terrified many people as much as the great Earthquake some years before, so that some people sat up the whole night.

Were observations and experiments made as far and with as much accuracy as the nature of the Phenomena will admit, there seems to be little ground to doubt but the true cause might be investigated. It might in this way be known, which I think is not yet certain, whether it be produced by electricity, or whether it must be accounted for from very dif ferent princples. Whether, after all, the nitrous acid may not be a principal cause? This acid is perpetually exhaled in vapors, and constantly floating in the atmosphere, as appears from the experiment of exposing to the air linen soaked in lixivium of alkaline salt, which in a certain time is found to be changed into vitriolated tartar. In a state of heat and dryness it combines instantly with phlogiston, will receive, at the same instant, the heat of ignition and form a kind of nitrous. phosphorus. Whether exhalations of volatile sulphurous acid may not be equally concerned, which is the least capable of concentration, and consequently will rise to the greatest

height in the atmosphere?

Either of these combined with

phlogiston, the component corpuscles are put in an igneous state, and if phlogiston be a pure element, distinct from the electrical fluid, as it is a most active principle, may be met with in the air and produce similar phenomena. That these acids may produce such appearances is probable from the easy experiment of Pyrophorus, which any person may make by taking alum, which is a vitriolic salt, and to two parts add one of sugar or flour, reduce them to a powder by heat, then prepare it in a glass matrass by a 2d heat. This powder secured in a phial from the open air acquires an igneous quality, and when a small quantity is poured out in the open air it spontaneously kindles into fire, if communicated to combustible matter instantly inflames it. Whether the frequent Aurore in the northern part of Europe, and almost incessant Aurora during the whole winter, and covering the whole hemisphere at Hudson's Bay, as related by Captain Middleton, does not seem to favor such an hypothesis?

But it is not my design to form any hypotheses. Experiments with Sir Isaac Newton were always the criterion veritatis, and yet we have a striking instance of the danger of trusting to hypotheses, in the mistake that great genius made, by taking it for granted, "that the heat of the sun is as the density of his rays; and then by a number of curious experiments on the heat of dry earth, boiling water, red-hot iron, etc., found the standard of our summer heat, and having annexed the mean density of the sun's rays, seems to have constructed, upon this foundation, his general scale of heat for the solar system. But all his conclusions necessarily fail, because the main proposition can not be supported. It therefore appears to me highly necessary that some such observations and experiments as I have hinted should be made, in order to a certain solution of this striking Phenomenon, and I presume every friend to science will be ready to promote whatever may tend to such a solution. I have mentioned it to Judge Oliver, of Salem, who seems to think it the only way to come at certainty, and supposes the American Philosophical Society would have proposed something similar before this time, if this unhappy war had not prevented. The extent of North America will

happily favor such observations if gentlemen of distinction in literature will promote it, and others can be found at proper distances, and at the extremes that are willing to undertake. Could the same observations and experiments be made in Europe at the same time the discoveries might be the more important.

I have taken the liberty to address this letter to you, sir, as I doubt not but you will be ready to encourage every attempt for farther inquiries and improvement in the Phenomena of nature, and when you return to College, if you think it of sufficient importance, you will be in a situation to do much in accomplishing something of this kind. I must beg you to pardon my prolixity-had no thought of running this tedious length when I sat down to write; but hope the nature of the subject, and the peculiar pleasure I take in natural science, tho' I find but little leisure to attend to it, will be some apology. I shall esteem it, if you find leisure, a particular favor to receive a line from you respecting this subject. And beg leave to subscribe.

With great respect,

Your most humble servant,

M. CUTLER.

[Dr. Stiles to M. Cutler.]

PORTSMOUTH, Feb. 2, 1778. Reverend and Dear Sir:-Your favor of 5th ult., filled with truly philosophical learning upon the Aurora Borealis, gave me great pleasure. The solution of this Phenomenon has exercised the adepts in literature hitherto to little purpose. Our inquiries and researches, however, ought to proceed, and will probably be at length successful. I have not time more than to give you thanks for your dissertation, which is truly ingenious, and which I propose to communicate to some of my literary friends, and finally to the Amer. Philos. Society. If I can find leisure, I may hereafter submit to you some speculations of my own on the same subjects.

My respects to Mrs. Cutler.

I am, dear sir, your affectionate brother,

EZRA STILES.

[For the American Academy of Arts and Sciences.] IPSWICH, Feb. 14, 1783.

TO PROF. EDWARD WIGGLESWORTH.*

Reverend Sir:-Want of leisure, and knowing that you were in a low state of health, has prevented my answering your request so soon as I should otherwise have done. I now send you the number of houses, families, males and females, married persons, unmarried males and females above 15, widowers, widows, males and females under 15, males and females between 50 and 60, 60 and 70, 70 and 80, and upward of 80, in this small parish, as they stood on the first day of this year. I have taken considerable pains to make this enumeration as accurate as possible, and have included white and black servants, and blacks who live in families by themselves.

While I was making this enumeration, I attempted to procure further information on this subject from the deliberate recollection of each particular family; but the frequent emigrations into back settlements, and interchanging of families with neighboring parishes, prevented my obtaining, with certainty, any thing material, except that sixty years ago the number of houses rather exceeded the present number, and that of the inhabitants must have been nearly the same.

The former account I sent you of births and deaths was not made out for complete years, and did not come down so late as the time of enumerating the inhabitants. I have therefore inclosed a table of births and deaths from the first day of January, 1772, to the first day of January, 1783, including eleven years. And also a table of diseases for the same time, in which you will see, under each year, the disease of which every person, between the same periods of life noted in the Table of Mortality, was supposed to die. I have no doubt but there may be errors in this table, but I presume there are none that are very considerable. It has been my practice to minute the disorder that each person was said to die of, in my

* Edward Wigglesworth was born in 1732. Graduated at Harvard, 1749. Was Hollis Professor of Theology from 1765 until his death, in 1794. He was one of the founders of the American Academy of Arts and Sciences.-The Memorial History of Boston.

register of deaths, with no other view than to satisfy my own curiosity, and have not done it with that care and attention that the importance of such a register now appears to me to demand. The principal errors, I suspect, are in the diseases. of children, who are incapable of describing their feelings, and the symptoms of particular diseases do not appear so distinct in them as in adults, and in the article of consumption, by which Physicians intend a disorder of the lungs, and of which they make several species; but every disorder that is attended with a wasting of the muscular flesh, though by no means pulmonic, is generally termed a consumption.

The reason that the number of inhabitants has not increased in this parish for sixty years past, when the births for the last eleven years are more than double the number of deaths, is wholly owing to emigrations into new settlements. By the former register kept in this parish, it appears that the rate of births and deaths for sixty years has been nearly the same with the last eleven. The inhabitants have not been very subject to epidemic diseases, or those which are generally more rife at particular seasons of the year. The situation of the parish approaches to a level, interspersed with small hills, and some quantity of low meadow and swampy land, four miles from the sea. The people, who are almost all farmers, are laborious and temperate; the water exceeding good, and the air generally very free and pure. Hence, you will see that calculations on American population can not be made from our old settlements. We not only lose the excess of annual births above annual deaths, by emigration, but those adventurers consist chiefly of the young, healthy and robust, on whom population principally depends, while the aged and invalids remain in their old habitations. The new settlements must, therefore, greatly exceed the old in the increase of population, in proportion to the number of inhabitants.

It is obvious that many important questions in civil society, respecting the annuities of widows and persons in old age, reversionary payments, and several other matters, can be determined only by a knowledge of the expectation of human life in various places, and this knowledge can be obtained only from registers of mortality in those places. But I apprehend that