94 REPORT — 1861. 



The oxide of cerium is not present in tlie form of Ki-yptolite, since the analysis 

 was made with perfectly transparent light-gi-een-coloured crystals. 



The matrix in which the moroxite crystals are imbedded consists almost entii-ely 

 of calc-spar. 



On the Composition and Properties of the Water of Loch Katrine, as supplied 

 in Glasgow. Bi/Dt.W&lJjAC^, F.C.S. 



The water of Loch Katiine is well known to he remarkably pure, and to have 

 the property of acting upon lead more extensively than any other natural water 

 known, if we except rain-water. This latter circumstance induced several of our 

 most eminent chemists to express the opinion that danger to the health of the 

 people of Glasgow might arise from the introduction of the water. 



The distance of the lake from the city is about 35 miles, and the author shows 

 that the water becomes altered very considerably in composition during its ti'ansit. 

 A minute and carefid analysis of the water was made in February last ; and for 

 comparison an analysis of the true Loch Kati-ine water, made in the spring of 

 1854, is also given, the numbers representing grains per gallon- 

 Loch Katrine. Glasgow. 



Lime -19 -47 



Magnesia " '10 '12 



Sulphuric acid '33 "36 



Chlorine '33 -30 



Alkalies and carbonic acid. . . . "12 "51 



Alumina and phosphates "10 '16 



Oxide of iron — trace 



Silica -01 -06 



Organic matter "80 "84 



1-98 2-82 



In the Loch Katrine water no carbonate of lime was found, while a direct deter- 

 mination of this compoimd in the Glasgow water gave -68 grain per gallon. This 

 carbonate of lime is supposed to be derived from sandstone and other rocks through 

 wliich the water flows. 



Jjoch Katrine water gave 7-5, and Glasgow water 8-5 cubic inches of gas per 

 gallon, which contained in 100 parts — 



Loch Katrine. ■ • - ■ Glasgow. 



Carbonic acid I'O ; 4-5 



Oxygen 33-4 29-9 



Nitrogen 656 65-6 



100 100 



The difference in. the total quantity of gases may be owing to variation of tem- 

 perature. The increase in the carbonic acid, accompanied by a corresponding 

 decrease in the oxygen, appears to be owing to the oxidation of organic matter, a 

 similar change occurring wnen the Loch Katrine water is kept in a closed vessel 

 for a week or two. 



Experiments on the action of the Glasgow water on lead show it to be much less 

 active in this respect than the original water of Loch Katrine, the quantity dissolved 

 during the first twenty-four hoiirs being about one-thu-d, and the idtimate result 

 after several weeks, the water being renewed every twenty-four hours, rather more 

 than half of the quantity dissolved by the original water under similar circumstances. 

 At the end of a month the proportion of lead dissolved by the Glasgow water 

 appears to remain steady at -jLth of a grain of lead per gallon, a quantity that is 

 just upon the verge of danger. 



Ou the large scale, vdth pipes and cisterns in actual use, the proportions of lead 

 dissolved were smaller. Tliree sets of experiments were made ; with an old f -inch 

 pipe previously, employed for two yeai-s for the conveyance of Clyde water, a new 

 ^-inch pipe; and a new cistern exposing 2i square feet of surface to each cubic foot 



