July 20, 1888.] 



SCIENTIFIC NEWS. 



67 



different sections has been of a very varied and extensive 

 character. 



Mr. T. G. E. Elger, who is well known in connection 

 with selenographical work, was elected President for the 

 ensuing year, in succession to Mr. W. F. Denning, of 

 Bristol, whose valuable labours in meteoric and planet- 

 ary astronomy have long been recognised. The report 

 of the Council included a reference to the resignation of 

 the Hon. Sec, Mr. W. H. Davies, and expressed a gratify- 

 ing tribute to his zeal and assiduity in performing the 

 arduous duties of his office for such a long period. His 

 energy and capacity for management has contributed, 

 more than any other cause, to the rapid development of 

 the Society, and to the high position which it has attained 

 amid kindred associations. Mr. Davies is succeeded by 

 Mr. W. E. Rowlands, and there is every prospect that 

 the future of the Society will be conducted on an equally 

 satisfactory base as in the past. There can be no doubt 

 that it is accomplishing a most useful purpose in banding 

 together and utilising the work of our astronomical 

 amateurs. The Journal, which is published monthly 

 during the sessional meetings from October to May, is 

 widely read, and contains papers on various branches of 

 the science by writers who are entitled to speak with 

 authority. The possessors of telescopes, and all those 

 who may either feel interested in astronomical theories 

 or in practical work, must naturally regard this Society 

 with sympathy and accord it their support, as especially 

 calculated to encourage and stimulate their efforts in 

 learning something more of the wonders of the heavens. 



Manchester Scientific Students' Association. — 

 On June 16th the members of this Association made an 

 excursion to Chelford for Capesthorn, under the leader- 

 ship of Mr. J. Hetherington. Owing to an unfortunate 

 delay, Mr. Hyde's botanical lecture on " Umbelliferae" 

 had to be delivered in the train. On June 30th a visit 

 was paid to the Manchester Ship Canal's Works at 

 Eastham, and the newly-discovered old footpath or road 

 inspected. 



Barrow Naturalists' Field Club. — The first excur- 

 sion of the season was made on June 30th to Ravenglass, 

 wherelhe ruins of Wall's Castle were inspected. A visit 

 was then paid to Ross Camp, on Muncaster Fell. 



Ludlow Natural History Society. — The annual 

 report of this Society has just been issued, and we re- 

 gret to find that the Society has been compelled to 

 draw upon its reserve fund. We trust the appeal to 

 the residents will be successful. 



Manchester Microscopical Society. — At the con- 

 cluding meeting, for the present session, of the mounting 

 section, the chairman, Mr. E. P. Quinn, in the course 

 of a description of nearly 100 slides exhibited by him, 

 said that they had been specially mounted to use that 

 evening to illustrate the micro-chemistry and physics 

 of the vegetable cell. As he desired to show them the 

 cells in a condition as nearly as possible like that of 

 the fresh tissues, he had mounted the specimens 

 mostly in fluid media and principally in a 0-4 per cent, 

 solution of sodium fluo-silicate, which, whilst having the 

 preservative effects of solutions of corrosive sublimate 

 or carbolic acid, did not, like them, tend to take away 

 the green colour which was in many cases so desir- 

 able to preserve. Another advantage in using it is that 

 it causes but little^alteration in the shape of the cells, 

 owing to its slight solubility (four parts in one hundred) in 

 water. It is sold as a disinfectant under the name of Salufer. 



POISONS AND POISONING. 



A Lecture delivered by C. Meymott Tidy, Esq., 

 m.b., etc, before the royal institution of 

 Great Britain. 



(Concluded from p. 46.J 

 T^HERE naturally follows on what I have said re- 

 specting this chemical action of poisons, the follow- 

 ing important question : — 



Given knowledge of certain properties of the elements, 

 such as their atomic weights, their relative position ac- 

 cording to the periodic law, their spectroscopic characters, 

 etc. ; — or given knowledge of the chemical composition, 

 the molecular constitution, together with the general 

 chemical and physical properties of compounds, in other 

 words, given such knowledge of the element or com- 

 pound as may be learnt in a laboratory — does such 

 knowledge aflord any clue whereby we may predicate 

 the probable action of the element or of the compound 

 respectively, on the living body ? 



1st. Let us limit our attention to the elements. 

 The starting-point of this inquiry was the toxic 

 properties of the metals. The work oi Blake (1841) in 

 this direction was afterwards extended by Rabuteau 

 (1867). Their observations led them to the general 

 conclusion that " the physiological activity of the metals 

 increased with their atomic weight." This broad general 

 statement was modified at a later period by noting that 

 the reverse was the case with certain groups of metals. 

 Thus potassium (39) is more poisonous than sodium (23), 

 and barium (137 more poisonous than calcium (41). 

 These facts led Rabuteau to the conclusion that any 

 comparisons of toxicity must be limited to the metals 

 belonging to the same group. Husemann and Richet, 

 however, pointed out that even this rule did not hold 

 good, seeing that lithium having an atomic weight of 7, 

 was far more poisonous than either sodium or potassium. 

 Experiments on the metals were further conducted by 

 Richet with the metallic chlorides. Grain by grain, at 

 intervals of forty-eight hours, he added the chlorides to 

 water in which he kept fish of a given kind. He then 

 recorded the maximum strength of the solution of the 

 metallic chloride in which these said fish would live for 

 forty-eight hours. The conclusion at which he arrived 

 was that the limits of the toxicity of a metal bore no 

 relationship either to its atomic weight, or to any other 

 chemical or physical characteristic of the metal. 



Bouchardat and Stewart Cooper, in a similar manner, 

 experimented with the non-metals. Selecting the haloid 

 group of elements, they noted that their toxicity was 

 inversely to their atomic weight, flourine (19) being the 

 most poisonous, and iodine (127) the least poisonous of 

 the group, chlorine (35.5) and bromine (80) occupying 

 their proper intermediate positions. But here again 

 the group theory was inevitable. What was true of 

 monad elements was not true of the elements" of higher 

 atomicity, the toxicity of selenium (79) being far greater 

 than that of sulphur (32). 



With these facts before us there arises this question, 

 Was a relationship to be expected between physiological 

 action and atomic weight ? One poison acts on muscles, 

 a second on nerves and nerve-centres, a third on the 

 blood : — Is it likely, even supposing a relationship to 

 exist between a certain group of elements and a given 

 organ or a given structure, that the relationship would 

 be the same in the case of all organs and all structures ? 

 These researches (the outline of which I have briefly in- 



