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POPULAR SCIENCE REVIEW. 
The Cause of Colour-blindness. — In a paper, published in one of the 
American Medical Journals, Dr. M. A. Fallen states that this condition is 
divided into two classes, viz., Achromatopsy, or an insensibility of the eye 
to colours, and Dischromatopsia , which is a species of insensibility to colours. 
Of these, one is hereditary: the other is acquired and often subjective. Dr. 
Pallen believes that the colour-blindness depends upon some abnormality of 
the vitreous humour, whose function he believes to be the correction of 
prismatic refraction. It is well known that the vitreous humour is com- 
posed of a great number of irregular-shaped compartments, containing 
gelatinous-like fluid. These cells are separated by septa, and it is the 
disturbance or abnormal condition of these septa to which Dr. Pallen attri- 
butes the irregular refraction which gives rise to colour-blindness. — Vide 
The British Medical Journal, March 16. 
Intermittent Fevers produced by Vegetable Organisms. — Some time since, 
we called attention to Dr. Salisbury’s observations, tending to support the 
theory expressed above. More recently, these ideas have been, in some 
measure, confirmed by Professor Hannon, of the University of Brussels. In 
1843, says M. Hannon, 11 1 studied at the University of Liege ; Professor 
Charles Morsen had created in me such an enthusiasm in the study of the 
fresh water algse, that the windows and mantlepiece of my chamber were 
encumbered with plates filled with vaucheria, oscillatoria, and confervse. 
My preceptor said to me : ‘ Take care at the period of their fructification, 
for the spores of the algae give intermittent fever. I have had it every time 
I have studied them too closely.’ As I cultivated my algae in pure water, 
and not in the water of the marsh where I had gathered them, I did not 
attach any importance to his remark. I suffered for my carelessness a month 
later, at the period of their fructification. I was taken with shivering ; 
my teeth chattered; I had the fever, which lasted six weeks.” — Ibid. 
February 23. 
Hyposulphites in Dysentery. — M. Paul records some cases of dysentery, in 
which great relief was given to the patient by the injection of solution of 
hyposulphite of soda. This substance also completely removed all smell. — 
Vide Bulletin de Therapeutique. 
Quantity of Bed Globules in the Blood. — Signor Mantegazza, of Pavia, has 
undertaken a number of researches on this subject. Having constructed a 
new form of instrument for estimating the number of the red corpuscles, he 
arrives at several important conclusions, of which the following are a few 
1. The maximum number of red corpuscles in the blood of a healthy man is 
5,625,000 per cubic millimetre of blood ; the minimum (found in the blood 
of an anoemic woman) being 2,250,000 in the same volume. 2. The colour 
of the face and lips does not indicate the presence of a large proportion of 
red globules in the blood. 3. Urea, injected into the veins, rapidly 
diminishes the quantity of blood globules, in seven days reducing the 
number to about one-fifth of the usual quantity. 4. The proportion of the 
corpuscles in rabbits is nearly the same as that of man. 5. The foetal 
rabbit has a larger proportion of red corpuscles than its parent. 
Medical Products of the Pine. — It is stated, by the Chemical Neivs , that 
these products are now being much used in Paris. We cannot vouch for 
the reported therapeutic importance of these substances, but, as it may 
