, 258 



SCIENCE. 



[N. P, Vol. IX. No. 216. 



{Vmhellularia caUfornica), a small tree of the 

 olive family. A volatile oil is distilled from the 

 leaves aud used for medicinal purposes, while 

 the fruits are eaten by the Indians after being 

 roasted to destroy an acrid principle which they 

 contain. 



In the regular program Mr. C. L. Marlatt 

 explained the difficulty and confusion which 

 has appeared in connection with previous at- 

 tempts at designating numerically the broods of 

 the Seven teen- Year Locust, or Periodical Cicada. 

 This insect presents two distinct races, or sub- 

 species, the more southern of which has a 

 thirteen-year period. Mr. Marlatt proposes to 

 use the Roman numerals from I to XVII for 

 the seventeen-year broods and then continue 

 from XVIII to XXX for the thirteen-year series, 

 thus providing a fixed designation for every 

 possible brood. Preceding nomenclatures of 

 the subject were compared with the new sug- 

 gestions by means of charts. The paper was 

 discussed by Messrs. Howard, Lucas, Gill, 

 Waite, Ashmead and Cook. 



Dr. E. A. de Schweiuitz explained the practi- 

 cal working of the serum treatment for swine 

 plague aud hog cholera. In the previous season 

 (1897) about 200 animals were treated, with a 

 loss of about 20 per cent., while of the re- 

 corded cases of uninoculated animals about 80 

 per cent. died. During the past season the 

 treatment was given to about 2,000, with a 

 loss of about 23 per cent., while of 4,000 un- 

 treated about 40 per cent. died. The slightly 

 greater percentage of loss this season is ex- 

 plained by the fact that the conditions of the 

 experiment were not as carefully controlled. 

 The difficulty of diagnosis renders it desirable 

 to use a mixture of the serums prepared for the 

 two diseases. 



Dr. Erwin F. Smith discussed ' The Effect 

 of Acid Media on the Growth of Certain Plant 

 Parasites.' Extended experiments with sev- 

 eral bacterial diseases of plants demonstrate 

 that some species of these are exceedingly sus- 

 ceptible to an excess of acid in the culture me- 

 dium. The very slow progress of some such 

 diseases was explained by the fact that they are 

 limited at first to the vascular system, the fluids 

 of which are alkaline, while those of the paren- 

 chyma are acid. Some of the germs refused, in 



fact, to grow at all in the media prepared with 

 the juices of their own host-plants, until the 

 acidity had been artifically neutralized, while 

 in others growth was greatly retarded. A 

 chart was exhibited showing the comparative 

 reactions of the various species studied, with 

 reference to a definite scale of acidity and 

 alkalinity. 



O. F. Cook, 

 Corresponding Secretary. 



MEETING OF THE NEW YORK SECTION OF THE 

 AMERICAN CHEMICAL SOCIETY. 



The January meeting of the New York Sec- 

 tion of the American Chemical Society was 

 held on Friday evening, the 13th ult. , in the 

 Assembly Hall of the Chemists' Club, 108 West 

 55th street, Dr. Wm. McMurtrie presiding. 



An arrangement for holding the meetings of 

 the Society regularly in the club building was 

 announced and ratified by unanimous vote. Re- 

 ports were made showing that the fuuds con- 

 tributed for the expenses of the midwinter meet- 

 ing had been sufficient ; that the library had 

 been moved to the club rooms, where it was 

 undergoing classification and arrangement, and 

 that the resident membership had reached one 

 hundred, and the non-resident uearly, if not 

 quite, as many more. 



The following papers were read : ' Determi- 

 nation of the Bromine Absorption of Fats,' P. 

 C. Mcllhiney; 'Indicators,' John Waddell ; 

 ' Exhibition of Apparatus for Washing Precipi- 

 tates,' etc., W. D. Home. 



Mr. Mcllhiney recommends the bromine 

 number instead of the iodine number for identi- 

 fying oils and fats, on account of the greater 

 rapidity of reaction, greater stability of the 

 bromine-carbon tetrachloride solution both be- 

 fore and during use, and the want of differen- 

 tiation by iodine, between addition and substi- 

 tution compounds in the reaction. 



Mr. Waddell showed some very pretty ex- 

 periments illustrating the behavior of indica- 

 tors, and explanatory of their adaptability to 

 acid or alkaline reaction, according to their re- 

 spective constitution. 



Phenolphthalein, a weak acid, reacts red by 

 dissociation in presence of a strong alkali ; in 

 presence of ammonia and alcohol the reaction 



