200 Bibliography. 



rediscovered C. Barrattii in New Jersey, and that it proves to be iden- 

 tical with the European C.jlacca of Schkuhr. We may also take this 

 opportunity to state that C. miser of Mr. Buckley, described in this Jour- 

 nal, Vol. xlv, p. 173, is probably identical with the C. juncea, Willd., 

 desci'ibed from specimens cultivated in the Berlin Botanic Garden, the 

 particular derivation of which cannot now be traced. A. Gr. 



10. Botanische Zeitung. (Berlin, A. Forstner. Subscr. 4f Pruss. 

 thalers per annum.) — This interesting botanical newspaper, which 

 commenced in January, 1843, is most ably conducted by Prof. Mohl of 

 Tubingen, the distinguished vegetable anatomist, and Prof. Von Schlech- 

 tendal, the well-known editor of the Linnsea. It is occupied with ori- 

 ginal articles upon vegetable anatomy, physiology, morphology, and sys- 

 tematic botany, and with brief but spirited reviews or critical notices of 

 new publications, accounts of the proceedings of learned societies, and 

 general botanical news. 



As this weekly gazette embraces within its scope the matter formerly 

 given in the Litter atur-Bericht of tbe Linncea, the supplementary de- 

 partment of that journal is now discontinued, and, having completed the 

 16th volume, a new series is commenced, under the slightly modi- 

 fied title of Linncea, ein Journal fur die Botanik, etc. ; oder Beitrage 

 zur Pflanzeukunde. A. Gr. 



11. Prof. Forties's Bakerian Lecture. — We have received from the 

 respected author, and perused with much interest, the lecture of Prof. 

 Forbes of Edinburgh, " On the Transparency of the Atmosphere, and 

 the Law of Extension of the Solar Rays in passing through it." Ef- 

 forts have been made from time to time by eminent meteorologists, to 

 determine the proportion of the sun's heat absorbed in passing through 

 the atmosphere, (a subject like that of atmospheric refraction, of great 

 importance to the most refined astronomical inquiries,) and the resources 

 of geometry have been combined with direct experiments, to ascertain 

 the law of extinction of the solar rays in passing through successive 

 strata of the atmosphere. But a more promising mode of establishing 

 this law, and of ascertaining the actual amount of loss of solar heat 

 from atmospheric absorption, is by simultaneous observations of the 

 comparative intensities of solar heat at different altitudes. Sir John 

 Herschel's actinometer supplied the instrument best adapted to such 

 observations. Furnished with several of these instruments, accompa- 

 nied by minute instructions from the illustrious inventor, Prof. Forbes 

 resorted to the Faulhom, a high and insulated mountain of Switzerland, 

 extremely well adapted to the purpose. He had the good fortune to 

 associate with himself Prof. Kamtz of Halle, likewise an accomplished 



