146 



SCIENCE. 



[Vol. XI. No. 268 



There were persons who could place in the proper class, solu- 

 tions containing one part of quinine in 500,000, and other sub- 

 stances in correspondingly high dilution, while some failed to detect 

 solutions of more than three times the above strength. In how far 

 this was due to education, we are unable to say. Among the men 

 examined were many who have been accustomed to handling and 

 recognizing drugs and medicines, and yet even these were fre- 

 quently surpassed by female observers who had no such training. 



In some previous experiments upon the sense of smell, of which 

 an account appeared in Nature {loc. cit), we noted almost as 

 marked superiority on the part of male observers. 



In a few cases, the ability to detect a dilute sweet was accom- 

 panied by a lack of ability to detect dilute bitters. This peculiarity 

 was, however, far from being a general one. 



As quinine is so largely used as a medicine, especially in the 

 Western States, it was thought that its habitual use might dull the 

 sense of taste for this particular substance. Among the observers 

 subjected to our experiments, the use or disuse of quinine seemed to 

 have had no especial influence. 



The experiments just described suggested several interesting 

 questions upon which we were unable to enter. How many, for 

 instance, of these substances, taken of equal delicacy-strength, 

 ■could be detected together in a mixture, in what order would they 

 be detected, and by what portion of the tongue or organs of taste } 

 Would all observers recognize them in the same order as to time ? 

 What would be the influence of the temperature of a solution 

 tasted, upon the delicacy of the sense of taste .' 



As to the degree of accuracy with which our results give the 

 average delicacy of the human sense of taste for the substances in 

 •question, we are led to believe from their substantial agreement 

 with determinations based upon the previous set of experiments 

 already alluded to, alike in the matter of absolute delicacy, of rela- 

 tive delicacy, for the various substances used, and of relative sensi- 

 tiveness of male and female observers, that they are but slightly 

 influenced by individual idiosyncrasies, and may be regarded as 

 fairly representative. E. H. S. Bailey. 



E. L. Nichols. 



On New Facts relating to Eozoon Canadense. 



In the February number of the Geological Magazine there is an 

 hiteresting article by Sir J. W. Dawson, ' On New Facts relating to 

 Eozoon Canadense.' In paragraph 9, ' Continuity and Character 

 of the Containing Deposits,' there are some remarks respecting the 

 stratigraphy of the Archaean or older crystalline rocks of Canada 

 upon which I wish to make a few comments. 



The author does not indicate what are, in his opinion, " the ex- 

 travagant statements respecting the older crystalline rocks now 

 being made," nor by whom they have been made. Neither does he 

 state what portion of the Laurentian system is referred to under 

 the term ' Middle Laurentian,' nor where he has recently exam- 

 ined it. 1 am not aware that Sir W. Logan ever used the term 

 ' Middle Laurentian.' As regards the ' continuity of the great 

 limestones ' over certain areas, and their intimate association and 

 interbedding with the gneisses, both orthite and anorthite, it has, 

 so far as I know, never been questioned. In some cases, however, 

 the limestones are very irregular, and occur in longish, more or less 

 lenticular bands interleaved with the gneisses, often in such a man- 

 ner as to suggest an origin posterior to that of the gneisses, or, 

 rather, to that of the strata from which they have been produced. 

 It is, I think, more than probable that original sedimentation of 

 calcareous matter, and subsequent segregation, have both operated 

 in producing the phenomena now observed in connection with these 

 great limestone belts, the latter somewhat analogous to that which 

 has produced the great ' quartz belts ' in the Nova Scotia gold- 

 fields. 



I must entirely dissent from the views expressed by the author in 

 correlating any of the so-called Upper Laurentian anorthosites of the 

 vicinity of St. Jerome, or elsewhere, with the Huronian rocks west 

 of Lake Superior. The massive anorthosites, as I have elsewhere 

 stated, are clearly intrusive, and the surrounding gneisses and lime- 

 stones do not pass beneath them ; and there are no grounds what- 

 ever for regarding them as an unconformable Upper Laurentian 



series. On p. 4, ' Report of Progress, Geological Survey of Canada' 

 1879-80,' I wrote, "If the foregoing determinations by Mr. 'Vennor, 

 which are given in his own words, are correct, they seem ver)' con- 

 clusively to prove, what I have already stated to be my opinion, 

 that the labradorite or Norian rocks of Hunt do not constitute an 

 Upper Laurentian formation, but occur in part as unstratified intru- 

 sive masses, and in part as interstratifications with the orthoclase 

 gneisses, quartzites, and limestones of the Laurentian system." It 

 is satisfactory to find that Sir William Dawson is now disposed to 

 admit that the " great masses of labradorite may be intrusive ; " but 

 when these are eliminated, nothing remains of the Upper Laurentian 

 as defined in any of these areas, from the Moisie River to St. Jerome ; 

 and unless the interstratified anorthite gneisses are made Upper 

 Laurentian, the term, so far as the Norian or labradorite rocks of 

 the areas named are concerned, must be abandoned, and I would 

 reiterate what I wrote in 1884 (' Descriptive Sketch of the Physical 

 Geography and Geology of Canada, 1884'): — 



" As regards the so-called Norian or Upper Laurentian forma- 

 tion. I have no hesitation in asserting that it has as such no exist- 

 ence in Canada, its theoretical birthplace. Wherever these Norian 

 rocks have been observed, they are either intimately and conforma- 

 bly associated with the ordinary orthoclase and pyroxene gneisses, 

 or they occur as intrusive masses when they present no gneissoid 

 or bedded structure. They clearly cut the surrounding gneiss, and 

 are probably due to volcanic or other igneous agency in the Lauren- 

 tian age." 



Considerable further investigation since the above was written 

 has entirely supported the view then expressed. 



Alfred R. C. Selwvn. 



Ottawa, March 13, 



Queries. 



30. Poisonous Jelly-Fish. — Last summer, while bathing on 

 the Maine coast, I had what was to me a novel and not very en- 

 joyable experience. While swimming I happened by accident to 

 kick some sort of an animal. For an instant the feeling that passed 

 over my feet was like a slight electric shock. Of course, I turned 

 to see what the animal was, and, from the glimpse which I had, I 

 should call it a red jelly-fish. For three or four hours after, my 

 feet were slightly inflamed and very pamful, the feeling being like 

 that caused by a burn. Afterwards I learned that a certain kind of 

 jelly-fish was said by fishermen thereabouts to be poisonous. Can 

 you tell me through your columns about this animal, what it is, 

 and how it stings, shocks, or poisons? What is the remedy for its 

 poisons .' Zoo. 



Boston, Mass., Feb. 29. 



Answers. 



30. Poisonous Jelly-Fish. — The above doubtless refers to 

 the effects of our common large red jelly-fish (Cyanea arctica). 

 Many jelly-fishes have the power of stinging soft-skinned animals, 

 and in this w^y ordinarily kill and secure their prey ; but there are 

 only a few species that have nettling threads powerful enough or 

 long enough to sting the human skin. On our New England coast 

 the only ones that are able to sting thus are the Cyanea, referred to 

 above, and the Portuguese man-of-war {Physalia); but the latter is 

 not common, and is rarely, if ever, found on the shore north of 

 Cape Cod. The Cyanea stings many persons very severely, espe- 

 cially if the tentacles come in contact with a tender part of the 

 skin, as the face, lips, eyes, or between the fingers, and of course 

 on any part of the body that is ordinarily covered ; but in my expe- 

 rience they will not sting the palms of the hand. The sensation is 

 much like that or the sting of a nettle ordinarily ; but in some cases, 

 or with some persons particularly sensitive to the poison, it results 

 in numbness, swellings, and subsequent eruptions, and even ulcera- 

 tions. The Physalia stings much more severely than Cyanea, and is 

 able to cause temporary paralysis of the arm or leg ; and in some 

 experiments it has been found to act in such a way as to affect the 

 heart : perhaps in a severe case it might even cause paralysis of the 

 heart. The nature of the poison is unknown, but it must be very 

 powerful, for the quantity is minute. A. E. V. 



New Haven, March 10. 



