Geology and Mineralogy. 77 



tion : CC1 3 . CHOH. CO a C s H 5 + (NaOH),=C0 9 Na. CHOH. CO,Na 

 + (NaCl) 3 +C 9 H 6 + (H 9 0) 9 . To prepare it, he adds to a 10 per 

 cent sodium hydrate solution warmed to 60° or 70°, the trichlor- 

 lactic ether slowly, in the proportion of one molecule of the latter 

 to 5 of NaOH. After standing a short time, dilute acetic acid is 

 added to weak acid reaction and then barium chloride solution so 

 lono- as this gives a precipitate. After cooling the precipitate is 

 filtered off and washed. It consists of pure barium tartronate. 

 The yield of the barium salt was about 50 per cent of the ether 

 employed. The trichlorlactic ether is readily formed from its 

 nitrile, chloralcyanhydrin, by passing hydrogen chloride gas 

 through its alcoholic, solution, heated on the water bath. And 

 the chloralcyanhydrin is produced by the action of hydrogen 

 cyanide upon chloral hydrate. From 1800 grams chloral hydrate, 

 the author obtained 2100 trichlorlactic ether. — Ber. JBerl. Chem. 

 Ges., xviii, 752, March, 1885. G. f. b. 



6. Pocket Book of Mechanics and Engineering, containing a 

 memorandum of facts and connection of practice and theory, by 

 John W. Nystrom, C.E. 18th edition, revised and greatly 

 enlarged with original matter. 672 pp. 12mo. Philadelphia, 1885 

 (J. B. Lippincott & Co.). — From 1854 to 1885 this valuable work 

 — small in size but large in the amount of matter it contains — has 

 gone through eighteen editions, and has increased twoand a half 

 times in size. It contains a vast number of facts conveniently 

 arranged and covering a wide range of subjects. Personal experi- 

 ence with an earlier edition has shown the writer how useful a 

 companion such a book can be. 



II. Geology and Mlnekalogy. 



1. Coals and Lignites of the Northwest Territory • by G. 

 Christian Hoffmann, Chem. and Min. Canada Geol. Survey. 

 From the Geol. and Nat. Hist. Survey of Canada. Montreal, 1884 

 (Dawson Brothers). — The coals and lignites of the Northwest 

 Territory have been studied with great thoroughness by Mr. 

 Hoffmann and with important results. The coal products are 

 divided into Lignites, Lignite Coals and Coals, and the three 

 groups are separately considered. The Lignites rather easily fall 

 to pieces on exposure, the hygroscopic water ranges from 10 to 

 17 per cent, and they all communicate a brownish-red color to a 

 boiling solution of potash; and they are all non-coking, in no 

 instance affording a coherent coke. The Lignitic Coals do not 

 easily disintegrate on exposure, the hygroscopic water varies from 

 8 to 9 per cent, they act with potash like the above but with less 

 deep color; and none yield a coherent coke. The coals are hard 

 and firm, bearing transportation without serious waste by reduc- 

 tion to pure coal ; they give but slight coloration to a solution of 

 potash ; they yield by fast coking a good coherent coke though 

 not by slow coking ; they contain but a small proportion of 

 hygroscopic water ; and in general appearance and chemical com- 



