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PROGRESS OF MICROSCOPICAL SCIENCE. 
Minute Structure of the Brain of the Insane . — This is a subject of 
considerable importance, the more so as some of our best authorities 
deny that the brain of the insane is materially different from that 
of the perfectly healthy man. The ‘ Medical Record ’ for April 14 
gives an account of a paper on this subject by an American physician, 
which is of interest. It is as follows : — Dr. Walter Kempster, of the 
Northern Asylum for the Insane, Oshliosh, Wisconsin, presented to 
the Chicago Society of Physicians and Surgeons some “ Notes on the 
Microscopical Appearances of the Brain of the Insane,” based on the 
examination of forty-nine cases. For a number of years Dr. Kempster 
has been making systematic microscopical study of the brain, and has 
examined the lesions of all forms of insanity, from acute mania to 
dementia, including puerperal and epileptic insanity. In each and all 
forms he has found a marked lesion — so that certain lesions may be 
grouped together as common to certain forms of insanity, to which 
lesions any particular type of insanity is palpably due. There is a 
wide difference between the lesions of acute and of chronic mania. 
1. In certain forms of insanity, and notably in dementia, the finer 
capillaries show marked indications of disease. The perivascular 
sheath surrounding the vessel is distended ; so much so, that some- 
times the vessel itself appears to lie in a tunnel, its calibre being 
much less than the sheath, doubtless due to repeated capillary conges- 
tions of the vessels — often diseased — irregular in calibre, suggesting 
the idea of aneurismal dilatations, hut entirely distinct from the 
miliary aneurisms ably described by Charcot. 
2. Next there is a degeneration, best studied in cases of dementia 
of syphilitic origin, and in the medulla oblongata, in the wall of the 
capillary, presenting dark-red patches at various points outside its 
walls, which gradually thicken, and appear to be due to a fatty meta- 
morphosis or atheroma. The description by Meynert, though accurate, 
is by no means so complete as could be desired. 
3. In 1871, while examining a section taken from the grey and 
white matter of the third left anterior convolution, there was found a 
peculiar appearance of the tissue. Situated in the white substance, 
but very closely to the grey matter, there were a number of small 
white spots, some round, some ovoid, clearly defined, in sharp contrast 
with the nerve-tissue, varying in size, from ^ to of an inch in 
diameter. These appeared to be of a granular consistence, and much 
more dense in structure than the surrounding brain-substance ; each 
was disconnected from the others, and normal white matter intervened. 
They did not absorb carmine, and were not connected with the 
capillaries. On the surface of some of the spots are fibres of connec- 
tive tissue and crystals of margarine. To determine the true character 
of theso spots and the degeneration, very elaborate and extensive micro- 
chemical manipulations were made. On allowing a section to dry, 
either with or without tho nitric acid treatment, these spots appear to 
