.322 



SCIENCE. 



[Vol. XIV. No. 353 



until it surpassed Lake Superior in size. In 1884 Mr. John Bignall 



■ of the Geological and Natural History Survey was ordered to com- 

 plete an unfinished survey of the lake ; and his v^rork, essentially 

 finished, appears in the report of Mr. A. P. Low, also of the Geo- 

 logical Survey. A carefully reduced copy of Mr. Bignall's map is 

 herewith presented ; some of the details, however, having been 



■ omitted for want of space. A casual inspection shows that not 

 only is Lake Mistassini insignificant compared to Lake Superior, 

 but also that it is not comparable even to Lake Ontario in size. 



'In examining the maps of Mr. Bignall and Father Laure side by 

 side, the differences are not so great as one might imagine. The 

 salient features are alike in both, and the one is easily reducible to 

 the other. The foreshortening in the latter probably arose from 

 placing too much reliance on the appearance to the eye. Every 

 topographer who has plotted a similarly shaped object, guided by 

 the eye only, knows that it is extremely difficult to avoid such dis- 

 tortion. 



The axis of the lake in Father Laure's map is certainly out of its 

 proper angle ; but, if we allow about 30° for variation of the com- 

 pass, this objection disappears. It is hardly probable that at that 



^early date Father Laure should have any means of estimating the 



Ptomaines and Leucomaines, and their Relation to Disease. 



Seeing the article in Science of Oct. 18 induces me to send you 

 this. It was published in a local medical journal [Pacific Medicaf 

 Journal, September, 1889), but I should be glad to give it wider 

 circulation. 



Some recent notices in regard to the composition of leucomaines, 

 and suggestions as to their probable relation to disease (Americajt 

 Microscopical Journal, vii. p. 216, 1888 ; Science, xii. p. 335, 1888 ; 

 Revue Scientifiqtie, xliii. p. 187, 1889), have induced me to embody 

 some reflections of my own on this subject. 



There is no longer any doubt that the announcement and gen- 

 eral acceptance of the germ theory of disease constitute one of the 

 greatest epochs in the history of medicine. But as in the case of 

 all great truths, so in this, the first ideas on the subject have had 

 to be greatly modified : the first extravagant hopes have been dis- 

 appointed or deferred, and the first claims of its advocates found to 

 be too sweeping. 



At first it was imagined that all the grave symptoms of a germ 

 disease, and the death of the patient, were due directly to the pres- 

 ence and multiplication of a specific microbe in the same sense as 



xtrait de la Carte du Domaine du Roi 

 Reverand Pere Laure, J^suiste, 



Map of Lake Mistassini reproduced from the official sur-veys of Mr. 

 A. P. Low, Geological Survey of the Dominion of Canada," 1886. 



REDUCED COPIES OF THE MAPS OF MR. BIGNALL AND FATHER LAURE. 



-variation of the compass, or that such a factor should enter into 

 his calculations ; so that, on the whole, there are but very few dis- 

 crepancies between the two maps that cannot be reconciled. 



Furthermore, except the direction of the axis, there are no differ- 

 ences between the outlines as shown by the two maps that might 

 not have resulted from the natural erosion of the basin and the 



■ corrasion of its outlet. " Rivers," as Gilbert aptly remarks, " are 

 the mortal enemies of lakes ; " and it is not reasonable to suppose 

 that Rupert River is an exception to the rule. " Le grand perce " of 

 Father Laure's map has been degraded to a narrow gash, and it is 

 by no means improbable that the level of the water has been con- 

 siderably lowered by drainage. Indeed, the fall between the adja- 

 cent lakes renders such an hypothesis highly probable, for a fea- 

 ture of such importance would not likely have passed Father 

 Laure's notice. Lac Dauphin has disappeared, — possibly from 

 having been drained, — and the long chain of islands traversing the 

 centre of the lake bears further testimony to the lowering of the 

 water in recent times. Unfortunately, Father Laure gives no esti- 

 mate either of the depth or of the area of the lake, beyond the allu- 

 sion " d'environ 300 lieiies de tour; " so that a comparison of these 

 elements at the two different dates is impossible. 



It goes without saying that the lake bears every indication of 

 glacial origin, and the severe winters of the present age cannot fail 

 to leave their traces on the outlines of the lake, even from year to 



-year. ■ Jacques W. Redway. 



the destruction of fruit trees and field-crops is sometimes due to 

 the ravages of insect-pests. The first great modification of this 

 original idea was, that the disease and death in these cases are not 

 due directly to the microbes, but to the accumulation in the blood (or 

 on the mucous surfaces to be absorbed into the blood) of a poison- 

 ous chemical substance, a by-product of microbian multiplication. 

 These by-products of albuminoid fermentation (for there are many 

 kinds) have now been isolated from their microbian culture-fluids 

 and analyzed.. They may be regarded as alkaloids of albuminoid 

 decompositions, and are called ptomaines. They are most of them 

 deadly poisons. Septic poison, which is the by-product of putre- 

 factive fermentation, i.e., of the multiplication of putrefactive ba- 

 cillus, is the most familiar example. 



The fact of a poisonous by-product of disease-germ multiplica- 

 tion ought to have been anticipated ; for every form of fermenta- 

 tion has its peculiar chemical by-product, and many of these are 

 poisonous. The different kinds of alcohol, ethylic, amylic, etc., and 

 different kinds of organic acids, such as lactic, acetic, butyric, etc., 

 are familiar examples. It would be strange indeed if the same 

 were not true of albuminoid fermentations determined by the 

 growth and multiplication of disease germs. As already said, 

 some of these chemical by-products of disease germs have been 

 separated from their generating microbes (as alcohol may be sepa- 

 rated from the yeast-plant) ; and, by the inoculation of these pure 

 chemical products, the corresponding diseases have been produced. 



