September 7, 18S3.] 



SCIENCi:. 



33:3 



I most cordially invite you to turn your attention to 

 some of the problems which vex the husbandman. 



PAPERS READ BEFORE SECTION F. 



Ou the use of vaseline to prevent the loss of 

 alcohol from specimen jars. 



IJV B. a. WILDKU AND S. II. OAOE OF ITUAC.\, X.V. 



In the absence of the authors of the paper, an 

 abstract of it was read by the secretary of the sec- 

 tion, Professor Forbes. Vaseline, when used for the 

 purpose indicated, proves to be an agent unaffected 

 by temperature, and by most chemical substances. 

 It is sparingly soluble in cold alcohol, but wholly 

 soluble in hot alcohol, solidifying ou cooling. It can 

 be fitly applied in sealing specimen-jars, aud meets 

 many requirements when so used. 



A nevr plan of museum-case. 



BY E. S. MOUSE OF SALEM, M.\.SS. 



The author described, and exhibited by means of 

 drawings, a new plan of museum-case. He said his 

 observations in the museums of Paris proved the 

 great inferiority of the ca>es there to those in the 

 United States. He gave, in addition to a detailed 

 plan of a case, some suggestions as to the best method 

 of arranging articles within. Jlr. Morse has had the 

 subject of arrangements for museum exhibitions 

 under consideration for several years, and the pres- 

 ent plan includes contrivances which he has previ- 

 ously suggested as separate devices. 



(liOTAS-ICAL PAPERS.) 



A supposed poisonous seatveed in the lakes 

 of Minnesota. 



BY J. C. ARTUUK OF CI1AKLE3 CITY, 10. 



In the summer of last year many cattle and hogs 

 died in the vicinity of Waterville, Jlinn. Residents 

 ill tlie locality believed that the animals were poisoned 

 by drinking the water of adjoining lakes. There are 

 two lakes of considerable size in the neigliborhood: 

 they are free from marsh, and have wooded borders; 

 through them runs a somewhat sluggish river. 



At the lime of the occurrence, the lakes showed a 

 quantity of dark-green scum on the surface, as well 

 as disseminated through the water. The snrface- 

 l.iyers of the scum were in places several inches 

 thick. The scum proved to be a water-weed, having 

 some chariicteristics like those of the nostoc, but is 

 known to botanists as Rivularia flnitans, and lias 

 been described by Colin, a European n.ituralist. The 

 plant is spoken of by the author of this paper as a 

 seaweed: he supposed it did not occur in this conn- 

 try elsewhere than in Minnesota, and it is not fre- 

 quent in Europe. 



Last year Mr. Arthur visited the locality of the 

 occurrence, and he repeated his visit this summer; 

 but in each instance too late in the sea.son to examine 

 the scum in xilu. It appear-s to be composed of in- 

 numerable small round bulbs of a transparent gelat- 



inous substance, which are filled with a dark-green 

 material. After lliey first begin to be seen on the 

 water, the bulbs increase in number with marvellous 

 rapidity. In about two weeks they begin to decay, 

 and their entire disappearance quickly ensues. These 

 phenomena take place usually in June. As no actual 

 experiments have been made uiwn animals, the deadly 

 qualities ascribed to the so-called seaweed are as yet 

 a matter of conjecture, though the reported facts 

 tend strongly to strengthen the belief that the plant 

 is poisonous. 



Relations of certain forms of algae to disa- 

 greeable tastes and odors. 



BY W. O. FAKI.OW OF C.VMBKIIXiK, MASS. 



Although large masses of any decaying vegetation 

 may render water unfit for drinking, the only group of 

 plants to be /eared, as far as their effect on the t.iste 

 and odor is concerned, is the members of the nostoc 

 family, which form flo.ating scums of a bluish-green 

 color. When exposed to a bright sun, especially in 

 shallow water, they are transformed into fetid, repul- 

 sive-looking masses of slime, which give to the water 

 the so-called pig-pen odor. The water-supplies of sev- 

 eral eastern cities have been thus contaminated, and 

 principally by species of Coelosph.ierium, Clathro- 

 cystis, and Anabaena. In Minnesota is the represent- 

 ative of a fourth genus, Kivularia, which was first 

 found last year at Waterville by Professor Arthur, 

 and which has been found to be very abumlant this 

 year in Lake Minnetonka; and in all probability it 

 occurs in most of the other lakes of this region. The 

 singular fact is, that while unknown elsewhere in this 

 country, the species was found several years ago by 

 Colin in Silesia, who named it Rivularia fluitans; and 

 it was detected also by Gobi near the Gulf of Riga. 

 It appears also to be very closely related to, if not 

 identical with, an alga abundant in certain parts of 

 England, referred by Harvey and more recently by 

 Philips to Echinella articulata, Ag. This is another 

 illustration of the very wide distribution of the 

 species of the nostoc family, of which we have other 

 recent illustrations in the Kostochopsis lobatns of 

 Wood, first described from the northern states, but 

 which has since been found to be identical with 

 Slazea Rivulariaides subsequently discovered in Hra- 

 zil, and with Hormaclis Quoyi found only at F.al- 

 mouth, Mass., and the Marianne islands in the Pacific. 



There is a strong probability, that in the future Min- 

 neapolis may be troubled by the decay of the different 

 nostocs floating in the lakes near the city, where they 

 are very abundant. As far as avoiding trouble from 

 these plants is concerned, undoubtedly river-water 

 is to be preferred to lake-water; but before many 

 years the Mississippi near Minneapolis- will be con- 

 taminated by sewage, and the water will pnibably 

 then be obtained from the lakes. If the sliallower 

 lakes near the city are used, there can be little doubt 

 that in summer Minneapolis will have the same 

 trouble as that experienceil in Boston. Even at 

 greater expense, the water should be brought from 

 large and deep lakes, especially those across which the 



