378 Miscellaneous Intelligence. 



6. Solar Light and Heat. — Mr. Powel has been engaged for 

 some time in experiments on solar light and heat. He has examined 

 the heating power of the prismatic rays, but chiefly with respect to 

 the effects, said to be produced, beyond the red end of the spectrum. 

 He has found that such effects are really produced, but has accounted 

 for their being observed in some cases and not in others, from cer- 

 tain differences in the coatings of the thermometers employed. He 

 has concluded from a number of experiments with different coatings 

 that this heating effect is similar in its relation to surfaces to common 

 radiant heat, and differs essentially in this respect from the heating 

 power ziit/tin the spectrum. He has made other experiments from 

 which the nature and origin of this effect, may, with great proba- 

 bility, be inferred. The details will soon be made public. — Ann. 

 Phil. N. S. 



7. Benzoic Acid in the ripe Fruit of the Clove Tree. — The clove 

 is the flower bud of the Eugenia Can/ophi/lata, and the ripe fruit 

 used formerly to be used in medicine under the name of Antophijlli. 

 In the latter, Mr. VV. Bollaert has observed crystals of benzoic acid 

 lining the cavity between the shell and kernel. 



8. Certainty of Chemical Analysis. — We mentioned at page 164, 

 the conclusions to which M. Longchamps had arrived, as the results 

 of his experiments oh the uncertainty of the means of chemical 

 analysis, at present in the possession of chemists. His experiments 

 convinced him that no certainty could be obtained. Mr. Phillips, who 

 has also examined this question, considers the inferences of M. Long- 

 champs as unsupported even by his own Memoire, and from his own 

 experiments is satisfied of their inaccuracy. Some sulphuric acid was 

 diluted and divided into eight parts, four of these were precipitated by 

 nitrate of baryta, and four by the muriate of baryta ; the precipitates 

 were carefully washed and dried, and then weighed, those from the 

 nitrate were 128.7 ; 128.0; 12S.3 ; 12S.6 grains, mean 128.4: those 

 from the muriate, 12S.1 ; 128.7; 128.0; 128.5; mean 12S.325. 

 These results are certainly very different to M. Longchamp's. — Ann. 

 Vlnl, N.S., vi., 289- 



Q. Correction of bulk of Gases for Temperature. — Some of our 

 elementary treatises on chemistry contain an inaccurate mode of 

 estimating the change of bulk in a gas, occasioned by variation of 

 temperature. They have directed tbat the bulk of the gas be divided 

 by 480, the quotient multiplied by the number of degrees by which 

 the temperature of the gas differs from the temperature to which it 

 is to be reduced, and the product added, or subtracted, according as 

 the actual temperature is below or above that referred to. But as 

 the expansion of a gas, for each degree of Fahrenheit is -^^ of its 

 bulk at 32° only, and at no other temperature the above rule is not 



