An Advertisement of Mr. boil, about the Loss of many of his Writings: Addressed to Mr. J. W. to be communicated to those Friends of His, that are Virtuosos, which may serve as a kind of Preface to most of his Mutilated and Unfinished Writings.  
AS for the Report that doubtless has reached your Ears, of the Loss of several of my Manuscripts, and the Defacing of divers Others, 'tis but too true; and I am very sensible of it. But yet 'tis not barely upon my own Account that I am so, but very much upon that of my inquisitive Friends, and Mr. J. W. in particular. For I cannot but be troubled that I find myself disabled to answer the Expectations they had, that I should gratify their Curiosity, by entertaining them with several Tracts upon Philosophical Subjects: And that some  Accidents that have of late befallen me, oblige me to dissuade them from expecting henceforward that I should present them with almost any Treatise, Finished and Entire. For having been for many years afflicted with a Weakness of Sight, that necessitated me, instead of Writing myself, to Dictate to Others; and having been necessitated to make several Removes, some of them with too much haste to permit me to take an exact care of my Papers, or keep all of them together, and take them along with myself from place to place: When not long since I had occasion to review and range them, I found to my Surprise, as well as Trouble, that I wanted four or five Centuries of Experiments of my Own, and other Matters of Fact, which from time to time I had committed to Paper, as they were made and observed, and had been by way partly of a Diary, and partly of Adversaria, registered and set down one Century after another, that I might have them in a readiness to be made use of in my designed Treatises. And together with these Matters of Fact, I found missing seven or eight Centuries of Notions, Remarks, Explications and Illustrations of divers things in Philosophy, which I had committed to Writing as they chanced to occur to my Thoughts, and which might have place among the same Papers with the abovementioned Experiments. How all these should come to be lost, whilst some other Centuries of Notes and short Memoirs, some of them Speculative and others Experimental, escaped, I can as little declare, as recover them. But to add to the Misfortune (for such it is to Me, though perhaps not to the World,) One whom I had ordered to do something with a Bottle of Oil of Vitriol, unluckily broke the Glass just over a flat Chest of Drawers, which I had purposely caused to be made for no other use, than to keep in it my own Manuscript Papers, whereof it had then good store. And though I happened to be at that time in the Room, and made haste to unlock the distinct Drawers, and take them out; yet the highly corrosive Liquor had made such haste, and such havoc, that several Manuscripts, and among them some that I most valued, were quite spoiled, insomuch that there remained not words enough undefaced to declare what Subjects they concerned; and that the other Manuscripts that mischievous Liquor had reached to, had some of them their Leaves half consumed, and others a greater or lesser part of them; and all that the Menstruum touched, it made so rotten, that notwithstanding all our diligence, what was once wetted, could never be retrieved.  
IT was. Natural enough that this concourse of Mischances should suggest to me, that I was to take new Measures in reference to my designed, but yet unpublished Writings. For first, it seemed reasonable, that either I should wholly suppress some Discourses, wherein I had made a considerable progress, but had not finished them, or else should at least acknowledge and give notice, they are imcompleat, and blemished with divers Chasms, since a great many Particulars are lost, that should have done more than fill up those Vacancies: Which Defects I cannot now supply, many of the Experiments having been made, when I had by me some such Drugs and other Materials, and such Exact Instruments and Skilful Workmen as I am not now furnished with, nor am able to retrieve. Besides that, I was then also some times befriended by Opportunities and favourable Circumstances, that I cannot hope for again.  
To this first Reflection 'twas Natural to add another; which was; That since I could neither discover nor imagine how most of the Writings lately mentioned (with some others about differing Subjects) came to be lost; the surest course (if not the only sure one) that I could take to prevent the like Accidents for the future, would be to publish from time to time; as fast as conveniently I could, those Remains and Fragments, as well as less mutilated Papers, that yet continued in my hands; premising to each distinct Bundle of them, an Admonition to those Readers that care for no Books that are not Methodical and Complete, that they were not only free, but desired to pass these by, as Pieces both Confused and Unfinished.  
I might add, that perhaps it may be more Prejudicial to the Author than to the Reader, that these Papers come forth with such disadvantageous Circumstances: Since for the most part, the Method of Writings that treat about Experimental Philosophy, is not much minded and remembered by the Reader, at least after the first perusal; the Notions and Experiments themselves, abstracting from the Order they were delivered in, being the things that Philosophers use to take Notice of, and permanently retain in their Memories. The Introductory Discourses and Prefaces to be met with among some of the very Incomplete Papers that accompany this Letter, may perhaps not be  nor altogether Useless to some Ingenious Men; who will not be displeased to find themselves Excited, and perchance somewhat Assisted, to take particular notice of some Subjects, that seem worthy of being more thoroughly considered and cultivated than yet they have been. And some perchance may think the Designs I had upon such Subjects, not unfit to be pursued by them in their own Way and Stile. And as for these heaps of Fragments, that seem to be more of a Chaotic Nature (if I may so speak;) Since the Particulars they mainly consist of, are Matters of Fact; their being huddled together without Method (though not always without Order) may not hinder them from being fit, if well disposed of, to have places some where or other in the History of Nature; and to become not Unserviceable Materials in the Structure that is aimed at in this Age, of 〈…〉 and well Grounded Philosophy.