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POPULAR SCIENCE REVIEW. 
reservoir falls it immediately accelerates in speed. Duplicate lines of f in. 
iron gas-piping extend beneath the train, with ingenious indian rubber con- 
nections between tbe carriages. Tbe breaks can be worked by sending the 
air through either line of pipes, so that if one fails the other remains 
serviceable, and further with two lines of pipes the carriages may be turned 
end for end, if necessary. The pipes not being in the centre line of the 
carriage, this could not be effected unless two symmetrical lines of piping 
were provided. The breaks are actuated by the air pressing on a piston 
in an air cylinder placed under each carriage. Hence the breaks can be 
instantly put in action by turning a cock and admitting air from the air- 
reservoir to the piping. The pressure of air in the reservoir is 60 to 70 lbs. 
per square inch, but it is usually regulated not to exceed 10 to 30 lbs. in 
the air-cylinders. The details of this break, which are most ingenious and 
most carefully worked out, cannot be understood without drawings, and for 
these we must refer the reader to u Engineering ” for May 24, where the 
invention is very fully described. 
MEDICAL SCIENCE. 
The Physiological Action of Tobacco has been very carefully studied by 
Herren Yogi and Eulenberg. They investigated the physiological action 
of (1) those bases volatile below 160° and (2) of those volatile between 
160° and 250°. Both portions act like nicotine, producing contraction of 
the pupil, difficult respiration, general convulsions and death. They act 
more quickly by the stomach than when sub-cutaneously injected, but even 
then are not as promnt as nicotine. On post-mortem examination, the lungs 
and air-passages wjfre found to be highly congested. They think that the 
disagreeable symp oms produced in the incipient smoker, and the chronic 
affections which excessive smoking produces, as well as the poisonous effects 
of tobacco-juice when swallowed, are due to the pyridine and picoline 
bases, and not to nicotine. They explain the fact that stronger tobacco can 
be smoked in cigars than in a pipe, by finding that more of the volatile 
bases are present in the smoke of a pipe ; more especially of the very volatile 
and stupefying pyridine ; while in a cigar, little pyridine and much collidine 
are formed. The authors compared this action with that of the bases ob- 
tained from other plants used for smoking,- with those from dandelion, 
willow- wood and stramonium, and with pure picoline from Boghead coal. 
The action was entirely similar, but, with the exception of the willow wood 
bases, they produced no contraction of the pupil. Picoline in vapour is ex- 
tremely poisonous, producing great irritation of the air-passages, convulsions 
and death. From these results the authors believe that the different effects 
of smoking opium are due simply to a difference in the proportion of the 
bases produced by its combustion. — Arch. Pharm. II. cxlvii. 130. 
The Supposed Syphilis Corpuscles. — The u Monthly Microscopical Journal ” 
of April, quoting from the “ Allg. Wiener Med. Zeit.,” says that the latter 
contains a serio-comic article on this discovery of Lostorfer, which, for a 
few moments, shook such men as Strieker, Hebra, and Skoda off their 
