1881.] 



MICROSCOPICAL JOUENAL. 



15 



disks, but spheres ; and also to ex- 

 plain the ^''luminous spot in the cen- 

 tre " which is, in fact, a dark spot. 

 This article concludes, with another 

 error, as follows : " With my best 

 glasses and a low light, I have never 

 viewed a corpuscle, old or young, that 

 did not resolve itself into a simple, 

 globular body, perfectly transparent, 

 enveloped in a thin inembranous sac, 

 which is the seat of color." 



Mr. Fairfield's " new high power 

 lens " has already made him ridicu- 

 lous among men of science, although 

 he still presses his claims for its won- 

 derful excellence. Messrs. Tolles, 

 Spencer and Zeiss might as well 

 give up business, if all that is asserted 

 of the new lens is true. It is clear, 

 from the above lucid explanation of 

 the physics of the microscope, that 

 angular aperture must be a delusion. 



We have read a number of articles 

 from Mr. Fairfield's pen, and we do 

 not hesitate to assert that he is either 

 wofully ignorant of science, or else 

 a consummate humbug. 



Alg^ in Drinking-Water. — 

 Professor W. G. Farlow, who is un- 

 questionably one of the best in- 

 formed crytogramic botanists in the 

 country, is the author of a pamphlet 

 of twenty-two pages, and two plates 

 — one a lithograph and the other a 

 heliotype-plate — entitled, " On Some 

 Impurities of Drinking-water, caused 

 by Vegetable Growths." The pam- 

 phlet is an extract from the " First 

 Annual Report of the Massachusetts 

 State Board of Health." The arti- 

 cle is written in a popular style, and 

 surely tends to allay any anxiety 

 which may be engendered by the 

 reading of extravagant newspaper re- 

 ports of the contamination of water 

 by plant-growths. The larger water 

 plants, Myriophyllum, Ceraiophyllum, 

 Callitriche, Utricularia, Anacharis, 

 Potamogeton, Naias, Vallisneria and 

 Lemna, for example, may be the 

 cause of trouble by choking the 

 small streams, or by affording places 

 of attachment for certain lower 



plants, which have already become 

 quite noted for the peculiar odor and 

 taste which they give to the water 

 during their decomposition. Among 

 the algae the grass-green, filamentous 

 species belong to the three orders, 

 Zoosporese, CEdogonieae and Conju- 

 gateae, besides a few filamentous Des- 

 mideae. The bulk of the larger 

 algae belong to the first and last or- 

 ders. These grass-green forms, how- 

 ever, do not act injuriously upon the 

 water ; in fact they do not grow ex- 

 cept in pure water. Some of the 

 bluish-green, purple, at times almost 

 black, algae, however, are not so harm- 

 less. Among these we have the 

 Nostocs, which are characterized by 

 cells arranged in filaments, and the 

 Chroococaceae, in which the cells are 

 united in colonies of no definite 

 shape. It is to these plants that the 

 noted pig-pen odor is due ; and when 

 large masses of them decay it is very 

 perceptible. In 1876, Horn Pond, 

 Woburn, became very offensive from 

 the decay of Anabcena, caused by the 

 lowering of the water and the intense 

 heat. In 1879 the water became 

 once more affected, this time princi- 

 pally by Clathrocystis. At South 

 Framingham, in the same year, a 

 green scum had formed upon a pond, 

 but the principal plant there found 

 was CcelosphcErium Kuetzingianufn, as- 

 sociated with which was AnabcBna 

 flos-aquce. Probably most of the 

 plants belonging to the family of Nos- 

 tocs, are capable of producing the 

 pig-pen Oder. The cucumber-taste, 

 however, cannot be said to be pro- 

 duced by any plant. 



o 



AlG/E Exsiccate. — Dr. VeitBre- 

 cher Wittrock, of Stockholm, and 

 Mr. Otto Nordstedt, of Sund, Sweden, 

 assisted by eight other algologists, 

 have issued Fascicles VII and 

 VIII of Prepared Specimens of 

 Algae. Each fascicle contains fifty 

 fine specimens, mostly fresh-water 

 plants, but also some marine forms. 

 They were collected principally in 

 European states, others are from Bra- 



