118 



Journal of Applied Microscopy. 



cord passing over pulleys, the size of 

 which can be changed for high or low- 

 power work. 



The condensing system, oxy-hydrogen 

 jet (Zirconium light) and sheet-iron 

 lanterns are carried on an optical 

 bench, made square, instead of pris- 

 matic in section; and the condenser, 

 computed by Mr. E. M. Nelson, is four 

 and one-fourth inches In diameter, per- 

 fectly achromatised and almost perfect- 

 ly aplanatic. The light from the jet is 

 first parallelised by the doublet con- 

 denser, which consists of two plano- 

 convex lenses having their plane sides 

 turned towards the radiant, the one 

 next the radiant being a quarter of an 

 inch less in diameter than the other, 

 and the focal length of the combination 

 being two and three-fourth inches, 

 taking up an angle of seventy degrees. 

 The parallel beam passes across an in- 

 terval of about ten inches, through a 

 screen or light-filter, and enters the 

 plano-convex lens of four and one-fourth 

 inches diameter (having its convexity 

 turned the other way to minimise aber- 

 rations, by which it is converted into a 

 convergent cone. This, after passing 

 through water in the chamber between 

 the lenses, is again parallelised by the 

 much smaller plano-concave lens, and 

 emerges from it as a slightly divergent 

 pencil rather less than an inch in diam- 

 eter. The plano-concave lens is of 

 highly dispersive glass, and perfectly 

 achromatises the whole system. The 

 whole system is provided with centering 

 screws, and an iris in front of the com- 

 bination next the light can be adjusted 

 to shut off the surplus light that is 

 reflected from the interior of the 

 miscroscope tube. 



P. E. B. JOURDAIN. 



Derbyshire, Eng. 



NEWS AND NOTES. 



Personals, news items, notices of meetings of 

 societies, conventions, etc., will be received up to 

 the twenty-second of the month preceding issue. 



Reports of three meetings of the New 

 Jersey State Microscopical Society have 

 been received. 



At their meeting of February 28, 18J8, 

 Mr. P. B. Kilmer, after calling attention 

 to the advance in ideas as to the neces- 

 sity of surgical cleanliness, explained 

 some of the commercial means (heat, 

 pressure, chemicals) of producing anti- 

 septic dressings, etc., showed on the 

 screen pictures of some of the appli- 

 ances for obtaining these results, and 

 also some of the more common germs at 

 the destruction of which he is aiming. 



Their meeting of March 28th, was given 

 over to the Botanical Section. Dr. B. D. 



Halsted and Messrs F. H. Blodgett and 

 J. A. Kelsey presented papers. 



By means of a series of charts. Dr. 

 Halsted explained the development of 

 exogenous stems from the early meris- 

 matic condition of the vegetative point 

 to that of the mature wood tissue. 



Mr. Blodgett gave the results of his 

 study on the development of Erythron- 

 ium from the seed to the mature plant; 

 also the development of new plants by 

 means of runners. 



Mr. Kelsey called attention to the ap- 

 pearance in this country ror the first 

 time in 1896 of the asparagus rust (Puc- 

 cinia asparagi, D. C.) ana the damage 

 which it is likely to do. It has been 

 known in Europe for a century. He sug- 

 gests Bordeau mixture as a preventa- 

 tive, and also refers to the parasite, 

 Darlucum tilum, Cast., as presenting a 

 possible solution of the problem, as it 

 attacks the uredo form of the rust. 



At their meeting of April 25th, repre- 

 sentatives of J. B. Colt & Co., of New 

 York city, exhibited their natural color 

 lantern and explained the processes by 

 which they obtain colored pictures by 

 means of violet blue, red, and green 

 screens. 



Publications Received for the 

 Journal Library. 



No. 13, Band XXIII of the Centralblatt 

 fuer Bakteriologie, Parasitenkunde u. 

 Infektionskrankheiten, Nos. 3 and 4 of 

 Vol VII of the Journal of Comparative 

 Neurology. The Bulletin of the Ohio 

 Hospital for Epileptics, and the Iowa 

 Health Bulletin, Vol. XI, No. 7. 



From the U. S. Department of Agri- 

 culture: "Standard Varieties of Chick- 

 ens, Fowls: Care and Feeding, Ducks 

 and Geese;" "The Country Slaughter- 

 house as a Factor in the Spreading of 

 Disease;" also the report of the Chief of 

 the Bereau of Animal Industry. We ac- 

 knowledge receipt of Bulletin No. 143, 

 N. Y. Expt. Sta., on the Cottonwood Leaf 

 Beetle. 



We are also indebted to Dr. A. W. 

 Bitting for his paper, "A New Photo- 

 micrographic Apparatus," from the Pro- 

 ceedings of the Indiana Academy of 

 Science; to Fred'k D. Chester for his 

 paper, "A Preliminary Arrangement of 

 the Species of the Germs Bacterium," 

 from the Ninth Annual Report of the 

 Delaware College Agricultural Experi- 

 ment Station, and to Dr. A. Mansfield 

 Holmes for the following separata: "The 

 Study of the Blood in Tuberculosis," 

 Journal of the American Medical Asso- 

 ciation, October 23, 1897; "A Clinical 

 Study of Tuberculosis Cases Treated 

 with the New Antiseptic Serum T. R.," 

 from the same Journal of Feb. 5, 1898. 



