Miscellaneous. 199 



face and pyramid in the case of several crystals was found to be 

 approximately 112°. One of the crystals exhibited at the meeting 

 was four inches across- 



A list of about twenty localities in Canada where molybdenite, 

 has been found was given, many of them being taken from the 

 reports of the Geological Survey. 



Eemarks were also made concerning octahedral crvstals of fluor 

 spar from the township of Hull and crystals of quartz from the 

 township of Portland, P. Q. Some of the latter are interesting on 

 account of their being terminated at one end by a single rhombo- 

 hedron while at the other end both the plus and minus rhombohe- 

 drons are well developed. 



Chemical — Algin and Alginic Acid. — After exposure to rain, the 

 long fronds of Laminaria stenophylla are observed to be swollen and 

 tumid, sacs of fluid being formed from endosmosis of water through 

 the membrane, dissolving a peculiar glutinous body. If these sacs 

 be cut, a neutral, glairy fluid escapes, which may be often seen par- 

 tially evaporated on the frond as a colourless jelly. This substance, 

 to which Mr. Ed. C. C. Stanford, F.C.S., has given the name Algin, 

 contains calcium, magnesium, and sodium, in combination with a 

 new acid which he has called Alginic acid. 



Algin, when evaporated to dryness, becomes insoluble in water, 

 but is very soluble in alkalies ; it is so abundant in the plant that 

 on maceration for twenty-four hours in cold sodium carbonate solu- 

 tion, the tissue is completely disintegrated, forming a thick solution 

 having fourteen times the viscosity of starch and thirty- seven' times 

 that of gum arabic. It is coagulated by alcohol, acetone and collo- 

 dion, but not by ether and precipitated by mineral acids, various 

 salts, and by lime w r ater and baryta water. 



It differs from albumen in not being coagulated by heat and from 

 gelose in not gelatizing on cooling, by containing nitrogen, by dis- 

 solving in weak alkaline solutions, and by its insolubility in boiling 

 water. From gelatin it differs by not reacting with tannin, and 

 from starch by giving no colour with iodine ; whilst its insolubility 

 in dilute alcohol and dilute mineral acids renders it unlike gum 

 arabic, pectin, tragacanth, and dextrin. It precipitates the salt of 

 the alkaline earths, with the exception of magnesium, and also the 

 salts of the metals, but it gives no precipitates with mercuric 

 chloride nor with potassic silicate. 



The uses to which Mr. Stanford proposes to apply the Algin are, 

 first — In sizing fabrics, a solution of sodium alginate imparting to 

 cloth and paper an elastic feeling, without the stiffness of starch. 

 2nd-. Containing about the same amount of nitrogen as Dutch 

 cheese (3.77 per cent.), and having a pleasant, marine taste, it may 



