TUBERCULOSIS. 
353 
ploy this method, which exposes the subjects to a premature 
death from a cause unconnected with phthisis. Moreover, it 
is not necessary to wait until the inoculation has produced 
tuberculosis of the lung before pronouncing affirmatively. 
The tubercular lesions propagate themselves in the guinea- 
pig with an admirable regularity, which we have formerly 
pointed out. If the inoculation has been practiced under the 
skin of the thigh, the superficial and deep inguinal lymphatic 
glands, the sub-lumbar glands, the spleen, a retro-hepatic gland, 
and then finally the lung, are successively invaded by the 
tubercular process. It suffices that these lesions shall have 
reached the spleen to have all the value as a diagnostic test, 
and they are ordinarily advanced to that point twenty days 
after inoculation. 
We advise, then, to practise subcutaneous inoculation at 
the inner face of the thigh on two or three guinea-pigs, and 
to proceed to the autopsy of these animals at the end of 
twenty days. 
With the object of shortening the delay necessary for this 
proof, M. Nocard advises the extirpation of the tumefied lym¬ 
phatic glands near the point of inoculation at the end of eight 
or ten days, and a search for the bacilli in their interior by 
means of scraping, staining, and microscopic examination. 
But all these proofs require one to be in possession of the 
virulent mucus. M. Nocard has remarked that it is rare that 
one can collect easily this mucus on the affected subject. After 
coughing the mucus is arrested in the pharynx, and the sub¬ 
ject swallows it. 
M. Poels has advised the making of a small tracheotomy 
wound at the root of the neck, in order to introduce as far as 
the origin of the bronchi a mop formed of a sponge fixed to 
the end of an iron wire. However slight this operation may 
be, it excites repugnance in the owners. M. Nocard has pro¬ 
posed to replace it by other methods less offensive. One can 
maintain the tongue of the animal out of the mouth by a 
vigorous traction, provoke a cough, and collect a mucus from 
the back of the tongue, One can also soak a sponge with 
mucus by rubbing it against the walls of the pharynx of the 
suspected animal by the aid of an appropriate instrument. 
