150 



Mr. G. F. Dowdeswell. Action of Heat [June 15, 



X4769, 

 \4634, 

 X4507, 

 X 4412, 

 X4253. 



Professor A. Herscliel and Dr. von Konkoly pointed ont long ago 

 that the spectra of periodic meteors belonging to different swarms 

 differ from each other, and the meteorites which come down to us 

 differ greatly in their chemical constitntion. It is not surprising to 

 find the matter of the nucleus of this comet to exhibit a chemical 

 difference from that of other comets. 



In the diagram, the width of the continuous spectrum corresponds 

 to the diameter of the nucleus. The bright bands extend into the 

 coma on the side next the sun. 



XVI. " On the Action of Heat upon the Contagium in the two 

 forms of Septichaemia known respectively as ' Davaine's ' 

 and ' Pasteur's.' " By G. F. Do wde swell, M.A. (Cantab.), 

 F.L.S., F.C.S., &c. Communicated by J. Burdon Sander- 

 son, M.D., LL.D., F.B.S., &c. Received June 15, 1882. 



Professor Bosenberger, of Wiirzburg, has recently published the 

 results of experiments,* by which he claims to have effectually 

 sterilised by heat, the blood and exudation fluids of the rabbit in the 

 two forms of septichsemia, known as those of Davaine and Pasteur ; 

 and he states that these fluids so sterilised, upon injection into other 

 animals, were found to be infective, reproducing the disease with the 

 recurrence of the specific organisms which characterise it : he there- 

 fore regards these organisms as having no causal connexion with the 

 affections in which they are found, but as merely secondary or 

 epiphenomenal. That this would be the necessary deduction from the 

 experiments mentioned, if it were proved that the fluids had been 

 effectively sterilised, is obvious ; but the account published contains no 

 details whatever of the methods employed, nor protocol of the ex- 

 periments, so that it is impossible either to discuss them or to form a 

 judgment as to the correctness of the conclusions. They, however, 

 involve a question so important in respect to the theory of contagium 

 vivum — the relations of these micro-organisms to disease — that it was 

 determined to work out the subject on the basis indicated in Professor 

 Bosenberger's paper, adopting such methods and precautions as 

 appeared necessary. 



* " Centralb. f. d. Med. Wiss.," 1882, No. 4, pp. 65-69. 



