BECEEATIVE SCIENCE. 



21 



and unjust self interest. If the theory of M. 

 Flourens he true, that a hundred years is the 

 true normal standard of man's life, then 

 assuredly Fuchs may have lost twelve of his, 

 by the adverse influence of disappointment 

 and vexation, which even the bravest admit is 

 felt on the failure of their legitimate hopes. 

 Fuchs, in early life, had little attention paid 

 to his really valuable discoveries. The world 

 was then too ignorant and scoffing to pay 

 attention to a man whose processes were 

 founded upon elaborate, yet unassailable che- 

 mical reasoning. Its scientific faith was in 

 inverse proportion to its ignorance. Let us 

 take care that a future generation may not 

 have to say the same of us. At the very period 

 at which Fuchs was vainly asking attention 

 to his views respecting water-glass, one Nice- 

 phore Niepce, of Chalons, on the Saone, 

 was here in England ready to unfold his re- 

 markable opinions in relation to light, and 

 to dispose of his marvellous processes of pho- 

 tographic drawing and engraving — processes 

 by which Daguerre was completely anti- 

 cipated ; but no one heeded him, and he 

 returned to France a disappointed man, as 

 we have lately learnt. Fuchs did not care 

 to conceal his disappointment, for he com- 

 mences his memoir with these words : — 

 " In 1825 I had an opportunity of pub- 

 lishing a paper on water-glass, which at that 

 time hoAvever did not meet with the attention 

 which the subject well deserved. It was 

 even stated that it difiered in no respect 

 from the well known ' liquor silicum' [water 

 of flints], and, consequently, was nothing new. 

 Experiments were made, but abandoned as 

 soon as they did not lead to satisfactory 

 results ; undertaken as they were without 

 the necessary knowledge or imderstanding. 

 Greater expectations were raised than could 

 in the nature of things be satisfied ; failures, 

 owing perhaps to faulty manipulation, fre- 

 quently caused the process to be abandoned 

 before it had been put to a fair test." How 

 complete a picture is this of the trials and 



obstacles that have to be borne and sur- 

 mounted by men who are philosophically in 

 advance of their time, or who have to cast 

 their suggestions amongst uncultivated, pre- 

 judiced, or selfishly interested minds ! May 

 we hope that the recital of such instances as 

 these wiU make the present generation pursue 

 more lovingly a wiser and more considerate 

 course — a course uponwhich,itis to be hoped, 

 we are now penitently inclined to enter. 

 Worthy Fuchs was obliged to chronicle, that 

 " There are always persons to be found who, 

 themselves unable to carry on experiments, 

 are always ready to condemn those of others, 

 upon the faith of a single experiment, in 

 which they failed ; as," says he, " I have ex- 

 perienced myself, more than once." He 

 adds, " An inert love of the customary and 

 habitual almost invariably exerted the usual 

 adverse influence." Shall we ever take 

 warning by the past, and learn to estimate 

 duly the "usual adverse influence "of many 

 things, " customary and habitual," amongst 

 us ? But, to suppress nothing, the good old 

 man, before his death, quaintly vrrites, "A 

 few years have changed much, and it has 

 been thought since that the water-glass, after 

 all, did not belong to the class of superfluous 

 things, and that few other bodies toere capable 

 of being put to so many various applications." 



Let us now make a few brief notes of 

 what these applications may be, and endea- 

 vour to get a rational idea of the chemical 

 and physical principles upon which they 

 depend. But, first of all, what is this water- 

 glass, and how can it be procured ? 



The water-glass, or soluble glass of Fuchs, 

 as it is designated in Gmelin's •* Handbook 

 of Chemistry," is, chemically speaking, a 

 tetra-sUicate of potash— a compoimd of si- 

 lica, otherwise called silicic acid, and potash. 

 The liquor silicum, already alluded to, is 

 a mono-silicate. There is also a bi-sili- 

 cate. Technically, Fuchs distinguishes four 

 kinds of water-glass— potash water-glass, 

 soda water-glass, double water-glass, and 



