284 ANNUAL OF SCIENTIFIC DISCOVERY. 



of persons, including many delicate ladies, even after it had 

 reached the bed-rock, some remaining as long as an hour in it 

 without any of them experiencing the slightest ill effects from 

 the pressure, and the fact that no cases of any importance what- 

 ever occurred among the workmen after the watches were re- 

 duced to 1 hour, satisfies me that this is the true cause of the 

 paralysis, and that, by lessening still more the duration of the 

 watches, a depth considerably greater can be reached without in- 

 jury to the workmen. Too long a continuance in the air-chamber 

 was almost invariably followed by symptoms of exhaustion and 

 paralysis. Dr. Jaminet, on one occasion, remained in 2i| hours 

 when the depth was over 90 feet, and was dangerously attacked 

 soon after reaching home. From the Report of tfie Chief Engineer, 

 Capt. James B. Eads. 



ICONO-PHOTOGRAPH ALBUM. 



An icono-photograph album, containing numerous figures of the 

 appearances presented by sections of the nervous centres, has just 

 been presented by Dr. Duchenne, of Boulogne, to the French 

 Academy of Medicine. He states he has obtained excellent re- 

 sults from sections of the great sympathetic nerve, the spinal 

 ganglia, the spinal cord, and of the medulla oblongata, when 

 magnified from 8 to 500 times. The plan was suggested some 

 years ago by Dr. Ducheune himself, but it was found that the pho- 

 tographs obtained in the ordinary method were not persistent. He 

 therefore fixed them on stone, by a process he terms photo-autog- 

 raphy, the details of which, however, he does not communicate. 

 It is satisfactory to find him stating that the results of his experi- 

 ment and photographs only confirm the substantial accuracy of the 

 beautiful drawing made by Dr. Lockhart Clarke on the central 

 parts of the nervous system, and especially upon the medulla 

 oblongata. In his later experiments Dr. Ducheune has adopted 

 Dr. Clarke's mode of preparation with chromic acid and carmine. 

 He states that certain micrographic details come out with wonder- 

 ful clearness in the photographs, and that by this means some 

 important additions may be made to our knowledge. Thus he 

 has ascertained that in the white substance of the medulla ob- 

 longata there are a large number of very small nerve tubules 

 (0.0033 m.m.) diameter mingled with others of average and of 

 large diameter m.m, 1 to m.m, 02 and .0.3. Nature. 



SKIN GRAFTING. 



We have already referred, at some length (" Lancet," July 7th, 

 1870), to the interesting experiments which are being carried out 

 at St. George's Hospital, by Mr. George Pollock, in reference to 

 the process introduced by M. Reverdin, of promoting the healing 

 of ulcerated surfaces by grafting upon them small pieces of healthy 

 epidermis. On Tuesday last we saw Mr. Francis Mason, at the 

 Westminster Hospital, attempt an adaptation of the process to a 



