426 



SCIENCE. 



[Vol. XIII. No. 330 



V. Unclassed Powders. 



Professor Cornwall says, in conclusion, " Our investigations 

 show, that, while especially the higher grades of creara-of-tartar 

 and acid-phosphate-of-lime powders are maintained at a quite uni- 

 form standard of excellence, the State is flooded, also, with many 

 baking-powders of very poor quality, — cheap goods, poorly made. 

 Of the thirty-nine brands examined, twenty-five contain alum or its 

 equivalent, in the shape of some soluble alumina compound ; eight 

 are cream-of-tartar powders, with small quantities of other ingredi- 

 ents in several cases ; four are acid-phosphate-of-lime powders ; 

 two belong properly under none of the above classes. 



" With one exception, the powders containing alum all fall below 

 the average strength of the cream-of-tartar powders, and in the 

 majority of cases they fall much below the better grades of the 

 cream-of-tartar powders. 



" In the cream-of-tartar and the acid-phosphate-of-lime powders, 

 no indications of substances likely to be injurious to health, in the 

 quantities used, have been found. 



" More evidence against the use of alum in baking-powders 

 might have been presented, but it would have been of a similar 

 nature to that which has already been given. In the writer's 

 opinion, the presence of alum in baking-powders is objectionable, 

 since, under certain conditions, it may exert an injurious effect on 

 the digestion. The effects may not be very marked in the case of 

 any individual consumer ; but that they can be induced to a greater 

 or less extent, seems to be well established. 



" There appears to be ample ground for requiring that the makers 

 of baking-powders should publish the ingredients used in their 

 powders, in order that the consumer, who may justly have doubts 

 of the desirability of using certain kinds, may be protected. " At 

 present the only guaranty of an undoubtedly wholesome and effi- 

 cient article appears to be the name of the brand. 



" Moreover, since it is quite possible to put up the baking- 

 powders in such a way as to preserve their strength very thor- 

 oughly, and since it is evident that many makers fail in this respect, 

 it would not seem unreasonable to require that baking-powders 

 should not be sold unless they will yield a certain percentage of 

 carbonic-acid gas. The bad effects of the ' heavy food ' prepared 

 with some of the baking-powders among our samples must cer- 

 tainly be felt by those who use them, and who are yet too ignorant 

 to know where the trouble lies. It is for this class especially that 

 nearly all legi.slation relating to securing good food and drugs is 

 enacted. 



" Since it is evident that some of the alum-powders are so pre- 

 pared as to increase the extent of any injurious effect, owing to the 

 mixture of ingredients whose combination cannot be justified on 

 any grounds, it is recommended that a special and more thorough 

 examination of such be made, with a view to preventing their 

 manufacture." 



THE MINERAL WEALTH OF BRITISH COLUMBIA. 



In 1877, Mr. George M. Dawson prepared, in connection with 

 the Canadian Government Surveys for the Canadian Pacific Rail- 

 way, a general note on the mines and minerals of economic value 

 of British Columbia, which was published in the " Railway Survey 

 Report " for that year, and was afterwards reprinted, with some 



additions, in the " Report of Progress of the Geological Survey for 

 1877-7S." Since that time great changes have occurred in respect 

 to the aspects of mining in British Columbia, and important addi- 

 tions have been made to our knowledge of its mineral resources 

 and geology. In view of these, and the increasing interest now 

 manifested in the development of the natural resources of the prov- 

 ince, and the numerous inquiries constantly received on that sub- 

 ject, it appeared to be desirable to place the available information 

 respecting its mineral wealth in the hands of the public in a sum- 

 marized form. With this object in view. Dr. Dawson began the 

 revision of the publication first referred to, but soon found, that, in 

 order to obtain a reasonably satisfactory result, it would be neces- 

 sary practically to rewrite the whole. The work has in consequence 

 assumed proportions larger than were at first contemplated, and 

 now appears as " The Mineral Wealth of British Columbia " (Mon- 

 treal, Dawson Brothers), with an annotated list of localities of 

 minerals of economic value. 



The object of this publication is twofold. It is, in the first place, 

 intended to serve in some measure as an exponent of the mineral 

 wealth of the province to which it refers ; to provide an answer of 

 a general kind to the inquiries now so frequently made on this sub- 

 ject ; and to collect for this purpose, in a convenient form, brief 

 summaries of the facts contained in the several official reports on 

 the geological features of the province, with specific references to 

 the pages in which they are treated of at greater length. In the 

 second place, it is designed to place in the hands of the " prospec- 

 tor" or miner a convenient synopsis of facts, with a list of localities 

 likely to be of interest to him. In the endeavor to carry out this 

 second purpose, it has been considered advisable to add notes on 

 such general principles, and to advance such suggestions, as, from the 

 study of the geological features of the province (dating from 1874), 

 appear to be of importance, and likely to be of service at the pres- 

 ent time in guiding the search for or exploitation of its metalliferous 

 deposits. In further pursuance of this object, some facts resulting 

 from late practice and investigations in other mining regions are 

 alluded to, and their application to the problems of development in 

 British Columbia is briefly noted. 



While the important developments now in progress in the prov- 

 ince appear to call for the present publication, it is to be antici- 

 pated that within a short time any thing that can now be said 

 regarding vein-mining will be relegated to a position of merely 

 historical interest. 



The province of British Columbia, with an area of 390,344 square 

 miles, includes a length of over 800 miles of the Cordillera belt of 

 the West Coast, — a region of mountains and of geological dis- 

 turbance, which, in this part of its extent, between the Pacific 

 Ocean and the elevated western margin of the Great Plains, has a 

 breadth averaging about 400 miles. This great mountain region 

 extends north-westward and south-eastward, and constitutes the 

 effective cause which has produced the similar trend of the Pacific 

 coast between the same parallels of latitude. It represents the 

 northern continuation of the most important metalliferous area of 

 the United States, essentially repeating its main orographic fea- 

 tures, though presenting also some notable differences of a general 

 kind, as well as many local peculiarities. 



The Cordillera belt, in British Columbia, may be described as 

 comprising four great mountain systems or principal axes of uplift 

 and geological disturbance, which are, in the main, nearly parallel 

 to each other and to the coast, — the Rocky, the Gold, the Coast, 

 and the Vancouver ranges. 



The Rocky Mountain range proper is the farthest inland, and 

 has an average breadth, in its southern part, of about sixty miles, 

 but is decreased near the Peace River to forty miles or less, and 

 apparently loses its importance and regularity locally where cut 

 through by the Liard, though recovering both still farther to the 

 north-westward. Near the 49th parallel, several summits occur in 

 this range which exceed 10,000 feet in height ; but northward few 

 attain this elevation till the headquarters of the Bow River are 

 reached. About the sources of the North Saskatchewan and Atha- 

 basca, the range appears to culminate, and Mounts Brown and Mur- 

 chison occur, with reputed heights of 16,000 and 13,500 feet respec- 

 tively. Near the. Peace, few summits exceed 6,000 feet, so far as 

 known. Though more or less extensive snow-fields occur in many 



