HARDWICKE'S SCIENCE-GOSSIP. 



123 



nished with numberless Objects hitherto little 1 



Known : 



ALSO 



Occasional Considerations on Gems, Poisons, the 

 Feyetation of Metals, the Resuscitation of Plants, 

 the Formation of Amber, Corals, and many other 

 Subjects. 



II. An Account of various animalcules never 

 before described, and of many other Microscopical 



DISCOVERIES, 



With OBSERVATIONS and REMARKS; 



LIKEWISE 



A Description of the Microscope used in the Ex- 

 periments, and of a new Micrometer, serving to 

 show the size of magnified Objects, 



Together with 

 Instructions for printing off any Meial or Coin, 



Illustrated with Seventeen copper plates. 

 By Henry Baker, Fellow of the Royal Society, and 

 Member of the Society of Antiquaries, London. 

 Rerum Natura nusquam magis quam in Minimis 

 tola est. 



Plin. Hist. Nat., Lib. si. cap. 2. 

 London : — 



Printed for R. Dodsley, at Tally's Head in Pall 

 Mall, ami sold by M. Cooper, in Pater noster Row, 

 and J. Cuff, Optician, in Fleet-street, 1753." 



"The author says that he spent ten years in mak- 

 ing "Experiments on a great, variety of saline Bodies 

 Mineral, Vegetable, and Animal, as well as many 

 other Substances" (one would like to know what 

 those other substances were) " both simple and com- 

 pound, whose parts cau be dissolved in Fluids, after 

 a method which has never hitherto been described 

 by any Author, or practised before myself by any- 

 body that I have heard of." 



"That particular Notice wherewith the Royal 

 Society was pleased to honour these Experiments, 

 encouraged me to prosecute them with all the Care 

 in my Power, to minute down every remarkable Cir- 

 cumstance in the Process, and to make faithful 

 Drawings of each Configuration." In a note ap- 

 pended to this paragraph we are informed that 

 "After many repeated Examinations of Salts and 

 Saline Substances by the Help of Glasses, in the 

 winter of the year 1743 1 had the Honour twice of 

 entertaining the Royal Society with a view of 

 their Configurations, which were then thought so 

 extraordinary, that very many of that illustrious 

 Body came often afterwards to see them more at 

 Leisure at my Lodgings, and in the Year 1744, Sir 

 Hans Sloane, Bart., late Piesidentof that Society, 

 was pleased et the recommendation of his worthy 

 Successor Martin Folkes, Esq., and of the Council 

 of the said Society, to bestow on me the Medal of 

 Gold, annually presented (as the Donation of Sir 



Godfrey Copley, Bart., of which Sir Hans is the 

 only surviving Trustee), to whomsoever of their 

 Members shall be deemed to have produced the most 

 extraordinary Discovery during the whole Year." 



In the second chapter, he describes his 

 method of preparing the various saline solutions 

 for his experiments with a minuteness almost 

 ludicrous ; these solutions, he says, mus' be made 

 with river or rain water, and that the water should 

 be saturated with the salt, so as always to be certain 

 of producing the same result : — "The Solution being 

 thus prepared, a drop of it is to be taken up with 

 a goose quill cut in fashion of a Scoop, and placed 

 on a flat Slip of Glass of about | of an inch in 

 width, and between 3 and 4 inches long. The slide 

 is to be warmed and placed on the stage of the 

 microscope, and the crystalization watched as 

 evaporation proceeds." 



Chapter III. deserves quoting in extenso, as it 

 shows the amount of chemical knowledge possessed 

 by a Gold Medallist of the Royal Society in 1743:— 



"It seems necessary, in order to make the 

 Matter in Hand understood the better, that some 

 Account should be given of what is meant by Salts 

 and Saline Substances, with some short Explana- 

 tion of the Dissolution of such Substances, and 

 their Crystalization afterwards, whereby the Differ- 

 ence between my Experiments and those of others 

 may become more evident. 



"Few will, I presume, imagine that Imean by Salts 

 such substances only as afford what is called a Salt 

 Taste, for Salts are of all Tastes, and Sugar itself 

 is no other than a Salt extracted from the Sugar 

 Cane. But we understand by Salts all Substances 

 whatsoever that are dissolvable in Water, or whose 

 Parts become so separated thereby as to disappear 

 therein, which notwithstanding the Water being 

 evaporated, shew themselves again combined in 

 some sort of angular Forms, with a Degree of 

 Transparency, and to the Taste are more or less 

 pungent. 



"To this may be added that they are fusible by- 

 Fire. 



" Salt, thus understood,is one of the first Principles 

 of the Chemists, and indeed has good Reason to be 

 esteemed so, as it enters into the Composition of 

 all Bodies. It is everywhere and in everything, for 

 if any Stone, Plant, or Animal be burnt a Salt 

 remains in the Ashes, which may be extracted by 

 Water and separated from the Caput Mortuum. 



" It is the nutriment of Animals, Vegetables, and 

 Minerals, insomuch that Herbs, Roots, Bread, &e., 

 deprived of their Salts can neither sustain, nourish, 

 or increase the Bodies of Animals, and the Earth, 

 when divested of it, becomes absolutely barren. 



" Vegetables and Animals, whilst flourishing and 

 alive, discharge, by Perspiration and other more 

 sensible Evacuations the Excess and Recrements 

 only of the Salts whereby they are preserved ; but 



g 2 



