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XXXIV. Ort a Case of Formation of Ice on an Alkaline Solution, 

 By Mr. Gavin Inglis. 



. To Mr. Tilloch. 



Dear Sir, ■ — J\ curious case came under my observation this 

 morning, ot" a formation of ice on a solution of asiies. It had so 

 much attracted the attention of the siervants before I got sight 

 of it, that a number of them were ranged round the boiler in a 

 state of admiration, looking at what they called t/ie patlerv, al- 

 luding to beautiful six-pointed stars of the most regular formation 

 which covered the surface of the liquor, each point bearing a most 

 striking resemblance to the termination of a full-spread fern leaf. 

 The most beautiful and perfect were in the centre, towards the 

 bides the same form of leaf continued, but they were laid rather like 

 a parcel of stars previously formed, thrown confusedly over one 

 another. The complete stars measured from the centre to the 

 point of the figure 2^ inches. The first glance of this ice struck 

 me as bearing a strong and marked resemblance to the snow ob- 

 served by Dr. Clarke during his stay in St. Petersburgh. I im- 

 mediately sent for that volume of his Travels, and on the spot 

 compared the figure given in vol. i. p. 12, and found it was im- 

 possible to give a more exact representation, than by extending 

 the dimensions of Dr. Clarke's fig. 1. The beautiful radiations 

 of tliis ice must have proceeded from the component parts of the 

 solution, which was made from ashes recovered from waste lees 

 highly carbonated, containing some ammonia and a portion of 

 nitre. The latter is formed in considerable quantity in the lees 

 jjuring the operation of bleaching, particularly when cottons are 

 under operation. The specific gravity of this solution was 1*1 15, 

 Two other boilers containing a solution of carbonate of potash, 

 the specific gravity 1'057 and 1 •073, were covered with a coat of 

 ice, soft and porous, better than an inch in thickness, rather re- 

 sembling wet snow slightly compressed, having no regular figure, 

 and little more adhesion than to admit its being taken off in flat 

 pieces: no appearance of lamination whatever, whereas the la- 

 minated ice was thin, solid, and shining. 



Dr. Clarke in his Travels, 'fth edit. vol. i. p. 11, marked on the 

 margin *' Extraordinary Phenomenon," says, " The season began 

 to chai.ge before we left Petersburgh, the cold became daily 

 less intense, and the inhabitants were busied in moving from the 

 Neva large blocks of ice into their cellars. A most interesting 

 and remarkable phaenomenon took place the day before our de- 

 parture ; the* thermometer of Fahrenheit indicating only nine 

 degrees of temperature below the freezing point, and there was 

 no wind. At this time snow, in the most regular and beautiful 

 crystals, fell gently upon our clothes, and upon the sledge as we 

 were driving through the street. All of these crystals pos-sessed 



exactly 



