A LOGICAL NOTATION FOR MATHEMATICS. 253 



Here it is necessary to point out that convenience in printing 

 justifies us in writing. 



S^x for {Sj-y 

 and that if we meant 



S operating on S.v. 

 wc should write it in the form So./-. But it is only in higher 

 mathematics that such forms are required. It is also only in 

 higher mathematics that the real value of a logical symbolism is. 

 fully realised, but that is no reason why it should not be used 

 throughout. We should never think of teaching children arith- 

 metic by means of the Roman numerals. For instance, this, 

 simple sum requires some working out : — • 



MDCCCLIX multiplied by CLXXIV. 

 The solution of such sums might be a fine mental training, such 

 as the learning of dead languages is asserted to be by som.e 

 enthusiasts, but as a weapon of attack in the battle of life, it 

 would be useless. So many students now learn mathematics with 

 a view to its future use in their career as mechanical or electrical 

 engineers, etc., that the subject should be taught them with the 

 practical end always in view. 



SLEEPING SICKNESS.— At a recent meeting of the 

 Royal Society the Sleeping Blckness Commission (CoL Bruce and 

 Capts. Hamerton and Bateman) submitted reports on experiments 

 performed with a view to ascertain (i) whether antelopes may act 

 as reservoirs for the virus of sleeping sickness, and (2) whether 

 there was any possibility of the domestic fowl acting in such a 

 manner. The conclusion was arrived at, in the latter case, that 

 the Uganda fowl cannot act as a reservoir of the virus. In regard 

 to antelopes a number of different species were procured from a 

 district where tsetse flies and sleeping sickness were unknown. 

 These bucks, after having been proved perfectly healthy, were 

 subjected to tsetse flies {Glossina palpalis), and after lapse of a 

 week their blood was inoculated into susceptible animals w^hich, 

 in everv case, became infected with trypanosomes. Young flies, 

 that had never fed before, were next fed upon the blood of the 

 bucks, being subsequently transferred to monkeys which in due 

 course became infected. The antelopes remained in perfect health 

 during the four months that they were under dailv observation, 

 and two of them never showed trypanosomes in their blood. 



CELTIUM, A NEW ELEMENT.— The discovery of a 

 new element by Urbain in the gadolinite earths, where scandium 

 and lutecium occur, was announced at the meeting of the Paris 

 Academy of Sciences on the i6th January. A quantity of gado- 

 linite had been worked up for the purpose of obtaining larger 

 amounts of lutecium, and in the mother liquor resulting from 

 several fractional crystallisations from nitric acid a new element 

 was found to be present bv spectroscopic examination. To this 

 element it is proposed to assign the name Celtium. Its spectrum 

 exhibits a large number of bright lines. 



