TRANSACTIONS OF SECTION B. 597 



and increase, and were composed of much salt, little siilplinr, and less mercury ; 

 the animals moved and ate, and were composed of much sulphur, little mercurv, 

 and less salt. ' I have some suspicions,' says Boyle, ' concerning this strange 

 relation; thougrh, as for the jreneration of livinuf creatures, both vegetable and 

 sensitive, it need not seem incredible, since we find that our common water, which 

 is often imprefrnated with a variety of seeds, lon^^ kept in a quiet place, will 

 putrefy, and then, too, produce moss and little worms according to the nature of 

 the seeds that were lurking in it.' 



I will give two short quotations from the ' Sceptical Chemist,' which show the 

 author at his best and his worst. In the first he is discussing the nature of 

 chemical combination between elementary particles : ' There are clusters wherein 

 the particles stick not so close together, but they may meet with corpuscles of 

 another denomination, disposed to be more closely united with some of them than 

 they were among themselves; and in such case two corpuscles thus combining, 

 losing that shape, size, or motion upon whose account they exhibited such a 

 determinate quality, each of them really ceases to be a corpuscle of the same de- 

 nomination as it was before ; and from the coalition of these there may result a new 

 body, as really one as either of the corpuscles before they were confounded. . . If 

 you dissolve minium in good spirit of vinegar and crystallise the solution, you 

 shall not only have a saccharine salt exceedingly different from both its' in- 

 gredients, but the union is so strict that the spirit of vinegar seems to be destroyed 

 . . . for there is no sourness at all, but an admirable sweetness to be tasted in "the 

 concretion.' In this passage we can distinctly see the germ of the modern theory 

 of chemical affinity uniting atoms into chemical compounds. In the second 

 quotation Boyle is arguing that fire is not only an analyser of mixtures, but 

 compounds the ingredients of bodies after a new manner ; mercury, for instance, 

 may be turned into a liquid, from which the mercury cannot be reduced again, and 

 consequently is more than a * disguise ' of it. ' Two friends of mine,' he says, 

 ^ both of them per.sons of unsuspected credit, have solemnly assured me that after 

 many trials they made to reduce mercury into water, "they once, by several 

 cohobations, reduced a pound of quicksilver into almost a pound of water, and this 

 without the addition of any substance, but only by urging the mercury with a fire 

 skilfully managed. Hence it appears that by means of fire we may obtain from a 

 mixed body what did not pre-e.xist therein.' Boyle has sometimes been charged 

 ■with credulity, and chemists who know how mercury has a way of disappearing 

 ■without leaving even its weight of water behind will smile to hear that the persons 

 of unsuspected credit responsible for this experiment were 'the one a physician, 

 the other a distinguished mathematician.' 



Boyle's writings contain the record of numerous important chemical observations, 

 e.g., the synthesis of nitre,and the preparation of nitric acid by the distillation of nitre 

 with oil of vitriol. He discovered several of the delicate tests we still use, e./;., solution 

 of ammonia as a test for copper, silver nitrate as a test for chlorides, gallic acid as 

 a test for iron. But I wish especially to refer to the work done by Boyle on the 

 air and its relation to combustion. The air, according to him, was composed of 

 three different kinds of particles : (1) exhalations from water and animals ; (2) a 

 very subtle emanation from the earth's magnetism, which produces the sensation of 

 light; and (8) a tiuid compressible and dilatable, having weight, and able to refract 

 light. It is this third portion of air which plays an active part in many chemical 

 operations. Like Van Helmont, Boyle recognised differences in gases, but did not 

 distinguish them as being something different in kind from air. He prepared 

 hydrogen by the action of hydrochloric and sulphuric acids on iron, but his chief 

 concern ■was to show that the new gas was compressible and was dilatable by 

 heat ; in other Avords, that it was really air. His observations are worth quoting"; 

 they contain, I believe, the first undoubted description of hydrogen, and the first 

 method devised for collecting and examining freshly prepared gases. 



' Having provided a saline spirit . . . exceedingly sharp and piercing, we put into a 

 viol a convenient quantity of tilings of steel, purposely filed from a piece of good 

 fiteel. This metalline powder being moistened with the menstruum was afterwards 

 drenched with more, whereupon the mixture grew very hot, and belched up copious 



