Ixxviii REPORT — 1855. 



all, I mean Organic Chemistry, which has received an especial impulse during 

 the last few years, an impulse mainly due to the genius of one distinguished 

 man whom we have the honour of numbering among our guests upon this 

 occasion. I think Baron Liebig will find in Scotland that kind of welcome 

 which a man of science values most, — a readiness to profit by his instructions, 

 and an enlightened appreciation among the farmers of the country of the 

 practical value of studying in their husbandry the laws which have been 

 revealed by his research. I am reminded, through the kindness of Dr. 

 Lyon Playfair, of some facts which give yet a more special interest to this 

 subject in connexion with our meeting here. It was to the British As- 

 sociation at Glasgow in 1840 that Baron Liebig first communicated his 

 work on the Application of Chemistry to Vegetable Physiology. The 

 philosophical explanation there given of the principles of manuring and 

 cropping gave an immediate impulse to agriculture, and directed attention to 

 the manures which are valuable for their ammonia and mineral ingredients; 

 and especially to guano, of which in 1840 only a few specimens had ap- 

 peared in this country. The consequence was that in the next year, 1841, 

 no less than 2881 tons were imported; and during the succeeding years the 

 total quantity imported into this country has exceeded the enormous amount 

 of 1,500,000 tons. Nor has this been all: Chemistry has come in with her 

 aid to do the work of Nature, and as the supply of guano becomes exhausted, 

 limited as its production must be to a few rainless regions of the world, the 

 importance of artificial mineral manures will increase. Already considerable 

 capital is invested in the manufacture of superphosphates of lime, formed by 

 the solution of bones in sulphuric acid, the use of which was first recom- 

 mended at the last Glasgow Meeting. Of these artificial manures not less 

 tlian 60,000 tons are annually sold in England alone ; and it is a cui-ious 

 example of the endless interchange of services between the various sciences 

 that Geology has contributed her quota to the same important end ; and the 

 exuviae and bones of extinct animals, found in a fossil state, are now, to the 

 extent of from 12,000 to 15,000 tons, used to supply annually the same ferti- 

 lizing materials to the soil. The exertions of Professor Daubeny of Oxford on 

 the same important subject, and the continued attention which he has de- 

 voted to it, have done much for the cause of agricultural chemistry in En- 

 gland ; whilst the thanks both of practical and of scientific men are due to 

 Dr. Lyon Playfair, and Professor Gregory of Edinburgh, for those admirable 

 translations of Baron Liebig's works, which have rendered them accessible to 

 every English reader ; and have thereby had no unimportant influence in 

 extending the knowledge of the laws aff"ecting both vegetable and animal 

 physiology. 



I am indebted to the same quarter for the mention of one i-emarkable in- 

 stance of the manner in which — to use Dr. Playfair's words — "the over- 

 flowings of Abstract Science pass into and fertilize the field of Industry." 

 One of the newest and most obscure subjects of chemical research has been 

 the discovery of certain conditions under which bodies, like in their com- 

 position, are nevertheless endowed with unlike properties, and thereby 

 become convertible to new purposes. It is in the application of this 

 principle that a gentleman of this city, Mr. James Young, has succeeded in 

 obtaining the illuminating principle of coal gas either in a solid or liquid 

 state ; and it has proved to be a substance of immense value for the lubrica- 

 tion of machinery, vast quantities of it being now manufactured and sold for 

 that purpose. 



I hardly know whether it is strictly in connexion with the advance of 

 chemical knowledge that I ought to remind you of one great discovery made 



