22 report — 1865. 



Again, the topograph may be used — ■ 



1. As a level ; 



2. As a clinometer, to obtain angles of elevation or depression, to find the dif- 



ference of altitudes of two stations, and to lay down contours. 

 The object of the topograph is to enable anyone, however unacquainted he may 

 be with mathematics, to become in a few minutes capable of surveying a road, 

 sketching a country, finding the heights of buildings and mountains, &c ; to enable 

 those who already possess a knowledge of surveying to survey almost as rapidly as 

 they walk ; finally, to enable those who are acquainted with geometry to represent 

 with accuracy the features of the ground in whatever districts they may find them- 

 selves. It is manufactured by Mr. Adie, 395 Strand. 



On an Instrument by which any Rainbow that can possibly appear within the 

 area of any picture, may be indicated in its right place and of the true si~c. 

 By Cornelitjs Tablet. 



CHEMISTET. 



Address by Professor W. A. Miller, M.D., LL.D., Treas. 6r V.P.R.S., P.G.S., 



President of the Section. 



Interesting historical associations are naturally awakened in the mind of the 

 chemist as he enters upon the business of this section of our scientific gathering in 

 the town whose hospitalities we are now sharing ; for he is reminded that on the 1st 

 of August 1774, only ninety-one years ago, Priestley laid, at Birmingham, the 

 foundation of modern chemistry, by the discovery of Oxygen. 



Yet it seems difficult to realize the fact that there must be some still living, who 

 entered life when the chemical nature of the atmosphere was undiscovered, when 

 water was believed to be an elementary substance, when the composition of the 

 ordinary acids, nitric, hydrochloric, and acetic, was unknown, when the discoveries 

 of Galvani had not been made, and when the battery which perpetuates the name 

 of Yolta did not exist. 



It requires a considerable mental effort to estimate aright the extraordinary 

 progress which chemistry, both in its scientific and in its practical aspect, has made 

 since that day. 



For example, the development of the laws of combination — the determination of 

 the equivalent proportions of the elementary bodies — the art of chemical analysis — 

 the Atomic theory — the isolation of potassium, with the consequent discovery of the 

 compound nature of the alkalies and earths — and the marvellous developments of 

 the organic department of chemistry, exhibit some of the most striking points in the 

 progress of the science ; whilst in the chemical arts we may mention gas-lighting — 

 the manufacture of stearic acid and other fatty acids for candles — the industry of 

 petroleum and paraffin — the chemical process of bleaching by chlorine — the prepara- 

 tion of carbonate of soda from common salt, and the extensive alkali trade. The 

 discovery of iodine and bromine, and their varied applications as remedial agents 

 and otherwise — the fascinating processes of photography — the development of the 

 trade in beet-root sugar — the extraction of quinia, morphia, and all the vegetable 

 bases, — these and other processes of chemical manufacture too numerous to men- 

 tion are all subsequent to, and may be said to be in nearly every case consequent 

 on, the great discovery of oxygen. 



Y, ell may we sympathize, now, in the sanguine anticipations of Priestley himself, 

 expressed in the preface to the volume in which this discovery is recorded, ' Ex- 

 periments and Observations on different Kinds of Air,' vol. ii. p. vi'i : — 'Tn reality, this 

 is not now a business of air only, as it was at the first ; but appears to be of "much 

 greater magnitude and extent, so as to diffuse light up >n the most general principles of 

 natural knowledge, and especially those about which chemistry is particularly con- 

 versant. And it will not be now thought very assuming to say, that, by working 

 in a tub of water, or a basin of quicksilver, we may perhaps discover principles of 



