1887.] MICROSCOPICAL JOURNAL. 115 
surrounded by the sludge, capable of revolution through the contents of the vat. 
Within the cylinders pumps create a partial vacuum and thus moisture is drawn out 
of the sludge to the amount of about 60% of its total. From the vat the half-dried 
sludge is drawn out on an endless traveling-web of very fine wire gauze 8 feet wide, 
supported by two rollers and passing over exhausters which remove 10% more of the 
moisture. The sludge now passes between 5 pairs of rollers and then into a hopper, 
whence it is fed into a cage on a lower floor and dried by a blast of hot air. It finally 
contains but 5 per cent. of moisture, is powdered and placed in bags for sale, as the 
product has a high manurial value. 
Dr. Frankland, to whose work in determining the numbers of bacteria in drinking 
water we have already referred, has exposed suitable sterilized cultivating media to 
air, at various places and dates, with a view to determining the conditions affecting 
the distribution of micro-organisms in the atmosphere. He found, in Io litres of air 
from Primrose Hill, 9 organisms, and in the same quantity of air from the bottom of 
the hill (100 ft.) 24. From the spire of Norwich Cathedral (300 ft.) 7, from the ground 
18. From air near the golden gallery of St. Paul’s 11, while in the churchyard 70. 
He determined that in air in a chemical laboratory 15 fell on a square foot in one 
minute, and 1,662 in a natural history museum. While in a railway 3d class carriage 
near London, window closed, no fewer than 3,120. In a barn during thrashing, as 
many as upwards of 8,000 organisms were determined as falling on one square foot in- 
one minute. Of the micro-organisms there were many different kinds; moulds, 
bacilli, micrococci, and various forms of yeast. 
Clinical microscopical technology is a series of articles by Dr. F. L. James, at 
present running in the S¢. Louis Medical and Surgical Journal. hey are in the 
same general vein as those upon more elementary topics, and will prove to be of great 
value. We need some simple and elementary work on the subject of clinical micro- 
scopical studies. Dr. James gives the methods to be followed. We trust he will fol- 
low them by an enumeration of the various objects found in urine, and their diag- 
nostic significance, together with description of those for which they may be readily 
mistaken. 
Microscope in dentistry, by Thos. L. Gilmer, M. D., D.D.S. In The Dental Re- 
view for May we find a brief article aiming to stimulate a wider use of the instrument 
among dentists. 
The journal of the Franklin Institute for March, 1887, contained an article of 
interest to those who are interested in the microscopic structure of rocks, upon the 
structure of iron and steel. The article is well illustrated by photomicrographs, The 
article gives an account of the tools needed in such study, and follows it with a de- 
scription of the appearance of both iron and steel. 
Water, heat, and cold, in their physiological action, forms the subject of a 
paper by G. F. Lydston, M. D., of Chicago. In it he considers the substance pro- 
toplasm as the ‘basic substance of tissues,’ and tries to trace back physiological pro- 
cesses to it where they belong. ‘The réle of protoplasm * * * appears to mea most 
important one, and too little thought of in our own studies of nutrition and the action 
of remedies.’ Thus, fevers show hypermetabolic activity of protoplasm, high temper- 
ature in consequence of the rapid metabolism, rapid loss of water in consequence of 
high temperature. By use of water in large quantities, dilute products of oxydation 
inhibit protoplasmic activity, and thus diminish heat, producing restoration of fluid to 
the tissues. 
CORRESPONDENCE. 
To THE EpiTor:—Since writing you, some weeks ago, I have made a slight modi- 
fication of the settling tube for urinary deposits, etc., said modification consisting in 
substituting, for the enlargement on the side of the tube, a small hole at the same 
point (z.e., about half-way up the side of the stopper—but, of course, not 77 the stop- 
per, but in the tube). The stopper is provided with a slot, as before ; and, in taking a 
drop from the lower end of the tube, it is a good plan to cover the small hole near the 
top-with the thumb of one hand, turn the stopper with the other hand until the slot 
