Notes and Memoranda. 81 



from fifteen to eighteen per cent, from cotton seed, which is very much 

 cheaper than linseed. The residue is nearly as valuable for fattening 

 purposes as linseed cake. The crude oil answers well for paints and 

 varnishes, and makes excellent soap. The refined is considered little 



inferior to olive oil. Two facts of great importance in medicine 



have lately been discovered. One, that in typhus fever, the interior 

 of the mouth is the seat of a putrid matter that constantly 

 poisons the air passing into the lungs, and becomes the haunt of 

 parasites. Several of the worst symptoms that accompany the 

 disease are now supposed to be due to this. It is removed without 

 difficulty, and to the great benefit of the patient, by very simple 

 means. The other is that the application of phenic acid in the 

 dressing of putrid sores not only prevents or removes the offensive 

 odour, and stops disorganization with great rapidity, but leads to a 

 speedy and healthful healing, even in the very worst cases. It is 

 applicable not only externally, but, notwithstanding its caustic 

 properties, internally also ; and it appears to be specially useful in 

 cases of an infectious nature. It has been found that pencil draw- 

 ings may be reproduced in any number, with great facility. For 

 this purpose they are to be moistened with dilute acid, and then 

 inked with a roller. Only the pencil marks will take the ink, and 

 the drawing may then be transferred to metal or stone, in the usual 

 way, by pressure. 



NOTES AND MEMOKANDA. 



Apparent Diameter of Shots. — Sir ¥m. Herschel endeavoured to find 

 the apparent diameter of Sirius as seen in a telescope, and freed from the enlarge- 

 ment due to optical defects. He estimated it at the tenth of a second. M. 

 Chacornac, availing himself of more recent apparatus, views the star through 

 what he calls a "prismatic telescope," and which the secretary of the Astro- 

 nomical Society supposes to mean " a double-image prismatic micrometer eye- 

 piece." M. Chacornac's letter, which appears in the Monthly Notices, does not 

 explain his method with sufficient distinctness. The society's hon. secretary (Mr. 

 Pritchard) points out that in the spurious discs of stars, as seen through teles- 

 copes, the light diminishes from the centre to the circumference of the principal 

 image, and varies in a similar manner through the series of rings with which the 

 star image is surrounded. He supposes M. Chacornac to form two images of the 

 spurious disc by means of double refraction, polarized in planes at right angles to 

 each other. When the prisms are rotated, the ordinary image is unaffected, but 

 the extraordinary image suffers gradual extinction, the weaker parts, or margins, 

 being extinguished first, and the centre last. If the star exhibited a true disc 

 in the telescope, it would remain, and be susceptible of measurement after the 

 spurious light surrounding it had been extinguished. When, however, the 

 spurious light is cut off, M. Chacornac found, with Foucault's great telescope, 

 that only an imperceptible point remained, so that the apparent diameter of 

 Sirius, freed from appendages resulting from the intensity of his light, resembled 

 the apparent diameter of a twelfth-magnitude star. 



Biela's Comet. — In a communication to the Astron. Nach., Dr. Qiacomo 

 Michez expresses a hope that when this body, which revisits us this year, ap- 

 proaches its perihelion in the beginning of 1866, decisive evidence may be ob- 

 tained concerning the two nuclei which were seen in 1852. In 1859 the feeble- 

 ness of the comet's light, and its immersion in strong twilight, precluded obser- 



