1885.] 



MICROSCOPICAL JOURNAL. 



2T 



further change. Thus we are fur- 

 nished with an example of organized 

 matter which for months or years 

 shows no evidence of life ; indeed 

 merely possessing a property which, 

 when acted upon by an appropriate 

 agent, gives rise to a series of actions 

 which we recognize as life. — Englisli 

 AJcc/iaiNc. from Loudofi Ti?}7cs. 



A 8olid Watch-Glass. 



Our readers have alreadv heard of 

 the solid watch-glass, devised some 

 time ago by Dr. A. C. Mercer, and 

 now favorabl}' known to many in\'es- 

 tigators as the vSyracuse solid watch- 

 glass. The illustration, Fig. ii. re- 



FlG. II. — The Sj'racuse Solid Watch-Glass. 



presents the glass. It is made of a 

 solid piece of glass, one svirface deeply 

 concave and the other slightly so. 

 They are furnished either j^lain or 

 with surfaces polished, as may be de- 

 sired. The most desirable form, 

 probably, on account of utility and 

 moderate cost, has upper and lower 

 edges and concave bottom, cut and 

 polished. 



The good features of this glass are 

 thus set forth in the circular adver- 

 tising it : 



' The Syracuse solid watch-glass 

 rests solidly upon the table, or micro- 

 scope stage, and is not liable to be 

 overturned and its contents spilled. 



' It is transparent and can be used 

 over black, white or colored paper, 

 enabling the student to use such back- 

 grounds to his work as will permit 

 him to watch its progress to best ad- 

 vantage. 



' In it, on the microscope stage, 

 can be examined from time to time, 

 or dissected and studied, transparent 

 tissues while in water, alcohol, oil of 



clove, or other bath, enabling the 

 student to reject unsatisfactory speci- 

 mens at any step in the process of 

 preparation. 



• When the top and bottom edges 

 are cut. one watch-glass rests dust- 

 tight upon another or receives accu- 

 rately a piece of plate-glass as a cover. 

 In such a watch-glass, covered, speci- 

 mens may remain for long staining or 

 soaking without becoming dirty and 

 without loss of fluid by evaporation. 



• When the concave surfaces are 

 polished, the watch-glass is as clear 

 as a lens and becomes a perfect re- 

 ceptacle for transparent dissecting 

 material on the microscope stage.' 



Having used some of the.se glasses 

 ourselves, and seen them in use in 

 laboratories, where they have given 

 the utmost satisfaction, we take pleas- 

 ure in commending them to micro- 

 scopists. They may be obtained from 

 , Dr. Mercer, Syracuse, N. Y. 



o 



('olored Rains. 



The following memoranda of col- 

 ored rains are, presumably, reliable, 

 but we have no clue to the compiler. 

 They are taken from a newspaper 

 clipping, and seem to be records of 

 observed phenomena of some kind. 

 The dates may prove of value to those 

 who have occasion to look up the 

 matter more fully : — 



On the 5th and 6th of November, 

 427 A. D., there was a fall of black 

 dust in the neighborhood of Constan- 

 tinople, and the atmosphere seemed 

 to be on fire. Marcellus ascribed it 

 to Vesuvius. 



Again, in 62£; a. d., red dust fell 

 in Constantinople. 



At Brixon, in the Austrian Tyrol, 

 in 869 A. D., red rain fell for three 

 hours. 



A red sand fell in Bagdad, in 939 

 A. D., and for many hours previous 

 and subsequently the atmosphere was 

 tinged with red. 



In 1056 A. D. there was a fall of 

 red snow in Armenia. 



In mo A. n., in the province of 



