260 



muscle, depending upon its having been previously boiled, by which 

 the globules were altered, their colouring matter separated, and any 

 connecting medium between them destroyed ; in such case, there- 

 fore, the skeleton only of the muscular fibre remained. 



The muscular fibre which was now selected for examination, was 

 taken from the fasciculi composing the great muscle that lies upon the 

 back of the bullock's neck ; it was examined within twenty-four hours 

 after the animal's death. By immersion in water, an integral fibre was 

 separated for inspection in the field of the microscope. Its mecha- 

 nism corresponded with that of the nervous fibre of a ganglion, but 

 the globules were larger in the proportion of -roW to WUTT and 4 ' , 

 parts of an inch. 



The gelatinous matter by which the globules adhere together is 

 less elastic than in the nervous fibre, so that the muscular fibre could 

 not be extended to double its length without breaking. 



The muscle of a trout exhibited the same appearance as that of 

 the bullock's neck, but the fibres were more brittle. 



From the facts stated in this lecture, together with those formerly 

 adduced respecting the structure of ganglions and nerves, Sir Eve- 

 rard observes, that they agree with muscles in consisting of single 

 rows of globules united by a transparent elastic gelatinous matter ; 

 the globules, however, differ in size, and the elastic medium is more 

 easily elongated, and restores itself more readily in a nerve than in a 

 muscle. An illustrative drawing accompanies this lecture. 



An Account of the Heat of July, 1825 ; together with some Remarks 

 upon sensible Cold. By W. Heberden, M.D. F.R.S. Read Janu- 

 ary 12, 1826. [Phil. Trans. 1826, Part II. p. 69.] 



The temperatures which Dr. Heberden wishes to record in this 

 paper, are those observed on the loth, 17th, 18th, and 19th of last 

 July, and were respectively 92, 90, 96, and 95. On the 15th, 

 the wind was S.W., on the other days it blew from the East. The 

 thermometer employed was sensible and accurately graduated, and 

 was suspended upon a lawn, about 5^ feet from the ground ; on the 

 first day, in the shade of a laburnum tree, and afterwards from an 

 external branch of a large Portugal laurel ; always distinct from any 

 building ; exposed to the full influence of the wind, and at the same 

 time sheltered from the actual rays of the sun, and from substances 

 heated by them. The author adds, that the only instance on record 

 of a corresponding elevation of atmospheric temperature was in July, 

 1808; on the 13th of which month, it appears from the Royal So- 

 ciety's register, the thermometer rose to 93 0< 5, and Mr. Cavendish's 

 thermometer, at Clapham, to 96. By way of comparison, Dr. He- 

 berden observes, upon the authority of the late Dr. Hunter, that in 

 the hottest season, and during the hottest part of the day, the range 

 of the thermometer, at Kingston, in Jamaica, is from 85 to 90. 



To these remarks, Dr. Heberden adds some observations on the 

 imperfection of the thermometer, as a measure of the degree of cold 



