I did hope with this to have given you assurance, that by retarding the hatching of seed, two crops of silk or more {27} might be made in a Summer: but my servants have been remiss in what was ordered, I must crave your patience till next year. * * * * * _An account of _Micrographia_, or the _Physiological Descriptions_ of _Minute Bodies_, made by _Magnifying Glasses_._ The Ingenious and knowing Author of this _Treatise_, Mr. _Robert Hook_, considering with himself, of what importance a faithful _History of Nature_ is to the establishing of a solid Systeme of _Natural Philosophy_, and what advantage _Experimental_ and _Mechanical_ knowledge hath over the Philosophy of _discourse_ and _disputation_, and making it, upon that account, his constant business to bring into that vast Treasury what portion he can, hath lately published a Specimen of his abilities in this kind of study, which certainly is very welcome to the Learned and Inquisitive world, both for the _New discoveries_ in _Nature_, and the _New Inventions_ of _Art_. As to the _former_, the Attentive Reader of this Book will find, that there being hardly any thing so small, as by the help of _Microscopes_, to escape our enquiry, a new visible world is discovered by this means, and the Earth shews quite a new thing to us, so that in every _little particle_ of its matter, we may now behold almost as great a variety of creatures, as we were able before to reckon up in the whole _Universe_ it self. Here our Author maketh it not improbable, but that, by these helps the subtilty of the composition of Bodies, the structure of their parts, the various texture of their matter, the instruments and manner of their inward motions, and all the other appearances of things, may be more fully discovered; whence may emerge many admirable advantages towards the enlargement of the _Active_ and _Mechanick_ part of knowledge, because we may perhaps be enabled to discern the secret {28} workings of _Nature_, almost in the same manner, as we do those that are the productions of _Art_, and are managed by _Wheels_, and _Engines_, and _Springs_, that were devised by Humane wit. To this end, he hath made a very curious _Survey_ of all kinds of bodies, beginning with the _Point of a Needle_, and proceeding to the _Microscopical_ view of the _Edges_ of _Rasors, Fine Lawn, Tabby, Watered Silks, Glass-canes, Glass-drops, Fiery Sparks, Fantastical Colours, Metalline Colours, the Figures of Sand, Gravel in Urine, Diamonds in Flints, Frozen Figures, the Kettering Stone, Charcoal, Wood and other Bodies petrified, the Pores of Cork, and of other substances, Vegetables growing on blighted Leaves, Blew mould and Mushromes, Sponges, and other Fibrous Bodies, Sea-weed, the Surfaces of some Leaves, the stinging points of a Nettle, Cowage, the Beard of a wild Oate, the seed of the Corn-violet, as also of Tyme, Poppy and Purslane._ He continues to describe _Hair, the