138 



THE AMEKICAN MONTHLY 



[July, 



NOTES. 



— Mr. Walmsley has become a liberal 

 contributor of ingenious devices for pho- 

 tographers within the past year or two, 

 and seems to be as much interested in 

 amateur photography now as he has been 

 in microscopy for many years. Walms- 

 ley's excelsior lantern is a new device 

 for the dark room, which is much cheaper 

 than some lanterns that are certainly not 

 better. We also read of Walmsley's 

 folding pocket lantern, phantom instan- 

 taneous shutter, instantograph shutter, ad- 

 justable view finder, alkaline developer, 

 ready sensitized paper, and photo-micro- 

 graphic camera. 



— A most valuable article for the pho- 

 tographer, especially for those who have 

 only occasionally to develop pictures, and 

 therefore are likely to be annoyed by the 

 deterioration of their solutions of pyrogal- 

 lic acid by long keeping, is the prepara- 

 tion of pyrogallic acid in tablets, just 

 called to mind by one of Mr. Walmsley's 

 circulars. Each tablet contains two grains 

 of the acid, which can be dissolved at the 

 moment of use, and thus a fresh solution 

 is always at hand, and there is no trouble 

 about weighing. 



— Some measurements of blood cor- 

 puscles have been made by Henry L. 

 Tolman and Marshall D. Ewell, M. D., 

 the results of which are recorded in The 

 Western Druggist. Mr. Tolman worked 

 with a Spencer homogeneous immersion 

 J„, n. a. 1.27, with an eye-piece micro- 

 meter in a ^ inch ocular, the value of 

 each division being ^^^ of an inch. Dr. 

 Ewell used a Spencer y\y, n. a. 1.35, a 

 Bausch & Lomb amplifier, a Bulloch cob- 

 web micrometer, each division of which 

 represented jxy^luffii of ^ri inch. The re- 

 sults are thus tabulated : 



Corpuscles. Largest. Smallest. Average- 

 Tolman... 50 ^Vir? jbVj ^tV? 

 Ewell 25 -^xY is^^i -JT^? 



— It was stated by Mr. J. J. Coleman, 

 in an address before the Philosophical 

 Society of (Glasgow, that microbes in ani- 

 mal flesh are not killed by the intense 

 cold of — 86° c. According to experiments 

 of his own and Prof. McKendrick, mi- 

 crobes alive before the freezing are again 

 brought into activity by heat and moisture. 



— Hedwigia, Organ fur Spec idle Kryp- 

 togamen kunde nebst Repertoriieiii fur 

 Kryptogamische Literaiur, begins its 

 twenty-fourth volume, enlarged, and in a 

 new dress. We are pleased to note this 



change, and trust that it will be met with 

 substantial appreciation by students of the 

 cryptogams. The first number of this 

 year contains an important article on new 

 species of the genus Riccicu, by F. Ste- 

 phani, illustrated by a plate. Hed%vigia 

 is edited by Dr. G. Winter, and is pub- 

 lished in Dresden. 



— A valuable report on the Purification 

 of Drinking Water by Alum, by Profes- 

 sor P. T. Austin and F. A. Wilbur, has 

 been issued from the chemical laboratory 

 ot Rutger's College. It has been found 

 that the addition of about 1.5 grains of 

 alum to a gallon of water will cause sus- 

 pended matters to subside in the course of 

 two days or more, leaving the supernatent 

 water clear. For domestic use the water 

 may then be filtered clear through a filter 

 of cotton batting pressed into the neck of 

 an inverted, bottomless bottle, a few min- 

 utes after the addition of alum. It is presu- 

 med, with good reason, that in this way 

 not only are suspended matters removed 

 from the water, but albuminoid and per- 

 haps other organic matters are also pre- 

 cipitated, or at least rendered incapable of 

 supporting the life of microbes. The quan- 

 tity of alum required is not sufficient to be 

 detected by taste, and, indeed, only the 

 slightest trace of alumina could be detected 

 by chemical tests in the water thus treated, 

 after the sediment was removed. The 

 method seems to be eminently practical. 



— The annual reception of the San 

 Francisco Microscopical Society was given 

 on the evening of May 19th. Thirty-eight 

 objects are named on the programrhe, one 

 for each microscope. According to the 

 report that has reached us the display of 

 objects was very fine, Mr. Hyde being 

 especially commended for the beautiful 

 way he showed some diatoms /;/ situ on a 

 dark ground, Mr. Breckenfeld for crystals 

 of kinate of quinia, Mr. Bates for his 

 colony of vorticellas, and Mr. Banks for 

 the display of the electric spark. 



■: — We receive regularly reports of the 

 meetings of the San Francisco Micro- 

 scopical Society, which is now one of the 

 most active of our societies. At a recent 

 meeting Dr. J. H. Stallard demonstrated 

 the method of cutting sections by freezing 

 the tissues with ether spray. At a subse- 

 quent meeting Mr. Banks showed the 

 electric spark under the microscope in its 

 passage between the terminals of a quar- 

 ter-inch spark induction coil attached to a 

 Grenet bichromate solution battery. Two 

 vulcanite slides had been prepared, on 

 which were fastened adjustable platinum 



