114 SIXTH RKPORT — 1836. 



therefore common to find them at their last transmutation changed into 

 a mixture resembling chalk and water, or even into solid calcareous or 

 bony concretions. Now as these substances are not found in coagula- 

 ble lymph, but are furnished in large quantities in the last transmuted 

 state of hydatids (acknowledged animals), a strong argument is thus 

 afforded against the present opinions respecting tubercles, and in favour 

 of those which the author supports. 



6. By feeding rabbits on unhealthy diet, in damp places where they 

 are deprived of exercise, hydatids and medullary tubercles will be pro- 

 duced in the course of a few months in the organs of the different cavities. 

 Doctors Jenner and Baron were thus able to produce hydatids, Avhich 

 were aftenvards transmuted into solid bodies. Mr. Carmichael by a 

 similar experiment ascertained that medullary tubercles might also he 

 produced ; and therefore, though he has no doubt but that tubercles are 

 frequently transmuted hydatids, yet he infers from his experiments that 

 they are also as often found ab initio in the medullary solid form. 



7. It is only on the principle of the parasitic origin and growth of 

 the tubercle, that we can satisfactorily account for those enormous 

 masses of tuberculous growth found in the abdomen and elsewhere, 

 which are not connected by vessels ivith the surrounding parts, are not 

 occasioned by inflammation, and which only destroy the patient by their 

 increase to an extent that interferes with the functions of the organs 

 in which they are imbedded or surrounded. 



In a M'^ork on cancer, published in 1806, Mr. Carmichael advocated 

 the independent vitality of that disease. At that period he supposed 

 that the entire mass was of zoophytic nature. He has now ascertained 

 that there are two distinct substances in the cancerous mass, — the one 

 medullary, the other cartilaginous. The first he considers to be the true 

 entozooa ; the last, which is capable of being injected, is part of the 

 parent animal, and the barrier which it throws out to protect it from 

 the progress of this entozooa. In cancer the great buUc of the morbid 

 growth is cartilaginous ; in fungus medullaris and fungus hematodes 

 it is medullary. Hence the more rapid progress and destructive nature 

 of the latter, which may generally be esteemed as constitutional, or 

 owing to some fault in the habit ; and hence the ill success attendant 

 upon all attempts to remove the disease by surgical operation. 



The author observes: "If my views of these diseases are correct 

 and founded in nature, another, but a lower link will be added to the 

 entozooa, which according to Cuvier belongs to the second class of zoo- 

 phytes." 



The following species may at present" be enumerated : 



1st. Tubercle of the lungs and other parts, whether commencing in 

 the form of a grey semi-transparent vesicle or of a whitish medullary 

 substance. 



2nd. Masses of tuberculous matter in the abdomen, which either 

 commence in the hydatid form, or in that of medullary tubercle ; these 

 are called by Dr. Baron tuberculated accretions. 



3rd. Fungus medullaris and fungus hematodes. 



4th. Carcinoma. 



