REVIEWS. 
509 
by the student, while in attendance on a course'of agricultural lectures. 
The subjects of chemistry, geology, and botany, of which agricultural 
science may be said to be compounded, find a place in this volume. More- 
over, the explanations are not couched in over-technical language, an 
advantage which most persons will gladly avail themselves of. The book 
professes to be an expose of the elements of the science, and it fulfils its 
title fairly ; there is, however, one serious objection to it, and that is, 
Liebig’s views are not represented. Mr. Johnston speaks of the operation 
of manures containing ammonia in large quantities as being beneficial to 
the soil. This is not correct ; the opposite is the truth. The only action 
of ammonia as a manure is to dissolve the more purely mineral consti- 
tuents of the soil, and by thus supplying them in larger proportion to the 
plant, to rob the former of its most valuable properties. Again, as the 
researches of Schoenbein have recently proved, the mere evaporat’on of the 
water from the surface of the earth gives rise to enormous quantities of 
nitrites, and consequently to nitrates of ammonia. Farmers need only 
supply the inorganic ingredients of plants, — the rest will be furnished by 
the atmosphere. This is the sheet-anchor maxim of Saxon and scientific 
agriculturists. 
We certainly cannot speak in any but terms of disapprobation of 
Mr. Fletcher’s brochure , which we regard as one of those mischievous 
productions calculated to suppress scientific inquiry, by wholesale asser- 
tions unsupported by the faintest shadow of evidence. Mr. Fletcher may 
be an analytical chemist, but he is certainly a bad reasoner, and a much 
worse physiologist. We should advise him to peruse Liebig’s last work, 
“ The JNatural Laws of Husbandry,” and also M. Blanchet’s letters to the 
Gazette de Lausanne of last December. Trusting that their influence may 
engender in him a more philosophic frame of mind, we bid him addio. 
AUSTRALASIAN CLIMATES AND PULMONARY 
CONSU MPTION."* 
HE consumptive patient is frequently advised to travel. The doctor 
advises a tour to Algeria, or the Pyrenees, or some such locality. 
It is not often, however, that we find Australia is the place selected. 
There appears, notwithstanding, to be much reason in support of the 
opinion, that the climates of our antipodes are calculated to arrest the 
progress of scrofulous diseases ; this, at least, appears to be the result of 
the experience of Dr. Bird, the author of the above-named treatise. 
Dr. Bird himself is one who, having been attacked by phthisis, left England 
for Melbourne, and after a comparatively short residence in the latter city, 
observed the gradual disappearance of his consumptive symptoms. Hence 
his essay will be read with anxious interest by all invalids who fancy 
themselves labouring under the scrofulous diathesis. En passant ■, we may 
* “ On Australasian Climates and their Influence in the Prevention 
and Arrest of Pulmonary Consumption.” By S. Dougan Bird, M.D., &c. 
London : Longman & Co. 1863. 
VOL. III. — NO, XII. 2 M 
