194 PROCEEDINGS OF SECTION B. 



ANALYSIS OP THE TOTAL SOLIDS. 



Sodium chloride ... ... ... ... 4.100 grains 



Organic matter and carbon di-oxide (loss) ... 1.812 ,, 



Silica 008 „ 



Iron, alumina ... ... ... ... ... .062 to .25 



Magnesium chloride ... ... ... ... .953 



Sodium sulphate ... .. ... ... ... traces 



Carbonate of lime ... ... ... ... .065 



7.000 



Little information can be directly derived from these analyses 

 as to its specific action on steam boilers, and in such cases the 

 analyst has often to gain his information from the incrustation or 

 corrosion produced, as the case may be. Analysis, moreover, does 

 not throw much light in some obscure cases of corrosion, and the 

 action of a water can only be known by actual experiment with 

 the metals themselves. 



Having frequently to examine and report upon various samples 

 of water as to their suitability for use in steam boilers, I have 

 hitherto been in the habit of estimating the amount of total 

 solids in a gallon, and then, by calculation, the quantity in a 

 hundred and in a thousand gallons respectively, according to the 

 amount of total saline matters present. Then, upon analysis of 

 the solids, a fair idea may be obtained as to the incrusting or 

 scale-pi-oducing or corrosive properties of the water. The presence 

 of the sulphates and carbonates of the alkaline earths are set 

 down as incrustants, while alkaline salts and organic matter are 

 likely to produce injurious sludge or corrode the plates by various 

 means. 



The relative amounts obtained of each of the above ingredients 

 pretty fairly determine the suitability of water for steam raising. 



The Colony of New South Wales, however, spreading, as it 

 does, over a great extent of territory, furnishes various samples 

 of water of almost every possible variety. Some of these give 

 results that perplex the analyst and which sometimes cannot be 

 brought under the rule I previously held to, namely, deductions 

 based on the analysis of the total solids. 



In addition, therefore, to the methods of ordinary quantitative 

 analysis, I would point out that T find it necessary in many cases 

 to extend my chemical examination so as to include the following 

 tests, which are, in some obscure cases, the only means, I believe, 

 by which the analyst can judge of the fitness of a given sample 

 of water : — 



I. A separate evaporation of the water in vacuo. 

 II. Estimation of the dissolved gases. 

 III. The character of the water as an exciting agent when a 

 voltaic couple is placed in the sample for a given time. 



