Contributions to Phenomena of Zodiacal Light. 17*<3 



along with kreatinine, it appears to be, in part at least, a substance 

 intended for excretion. Its crystalline character renders this pro- 

 bable ; and, at all events, if it has any function to perform in the body, 

 that function is not yet known. It must be regarded, in the mean 

 time, as one of the numerous series of less complex products derived 

 from the decomposition, in the body, of the effete tissues ; and al- 

 though we cannot yet produce it artificially, yet, from the rapid pro- 

 gress recently made in the study of the products of decomposition of 

 the albuminous substances, we may hope soon, not only to do this, 

 but also to discover, from these products, the true formulae of the al- 

 buminous compounds. 



2. Notices of a Flood at Frastanz, in the Vorarlberg, in the 



Autumn of 1846. By William Brown, Esq. 



3. Contributions to the Phenomena of the Zodiacal Light. 



By Professor C. Piazzi Smyth. 



The purport of this paper was to place on record certain observa- 

 tions made during the years 1843—4—5, in the southern hemisphere, 

 at those times of the year when the Zodiacal Light cannot be seen 

 in the Northern hemisphere ; to test, by means of these new data, 

 — which, besides the novelty of the geographical position, had the 

 further one of being determined by instrumental measurement, — 

 what laws of the phenomena may be considered to have been satis- 

 factorily made out, and what required further elucidation ; and to re- 

 commend these latter to the attention of observers situated in more 

 favourable parts of the world than those commanded by European 

 Observatories generally. 



After discussing the history of the subject, and mentioning the 

 results arrived at by different observers, the author mentions the 

 manner in which his attention was first particularly directed to the 

 subject, describes the particular course of observation which he then 

 commenced, and which consisted principally in observing the right 

 ascension and declination of the apex of the light, by means of a 

 small equatorial instrument of particular construction, which gave 

 results not affected with more than 2° of probable error. Combin- 

 ing his own observations with those of former investigators, the 

 author concludes, that the hypothesis proposed by Cassini, and sub- 

 sequently maintained by Laplace, Schubert, Poisson, Biot, and Hum- 

 boldt, viz., that the Zodiacal light is in the form of a ring en- 

 circling the sun, is decidedly untenable, but that it is rather, as first 

 suggested by Marian, and since affirmed by Olbers and Sir John 

 Ilerschel, in the form of a lenticular mass. Marian's idea, too, of 

 the body being exccntrically disposed about the sun, being endued 

 with a rotation, and occasionally crossing the earth's orbit, seems to 

 be confirmed. But the exact quantity of such excentricity, the pe- 

 rio'l of rotation, the position of the piano of the body, the question of 

 any actual periodical increase in the size and brightness of the Zo- 



